diff --git a/02-getting-started-bit-curator.html b/02-getting-started-bit-curator.html
index 66f57a7..5af17c0 100644
--- a/02-getting-started-bit-curator.html
+++ b/02-getting-started-bit-curator.html
@@ -333,7 +333,7 @@ <h3 class="callout-title">Getting around in BitCurator<a class="anchor" aria-lab
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution1" aria-expanded="false" aria-controls="collapseSolution1">
   <h4 class="accordion-header" id="headingSolution1">Show me the solution</h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
 <div class="accordion-body">
 <p>Getting around: Answers will vary, depending on what you choose to
 look at. At minimum, you should look at the various “Applications” (menu
diff --git a/03-imaging.html b/03-imaging.html
index 47a49f5..5366bc5 100644
--- a/03-imaging.html
+++ b/03-imaging.html
@@ -475,12 +475,12 @@ <h3 id="mount-disk-image-using-bitcurator-mounter">Mount disk image: Using BitCu
 </div>
 </section><section id="activities"><h2 class="section-heading">Activities<a class="anchor" aria-label="anchor" href="#activities"></a>
 </h2>
-<hr class="half-width"><div id="discussion1" class="callout discussion">
+<hr class="half-width"><div id="challenge1" class="callout challenge">
 <div class="callout-square">
-<i class="callout-icon" data-feather="message-circle"></i>
+<i class="callout-icon" data-feather="zap"></i>
 </div>
 <div class="callout-inner">
-<h3 class="callout-title">Challenge<a class="anchor" aria-label="anchor" href="#discussion1"></a>
+<h3 class="callout-title">Challenge<a class="anchor" aria-label="anchor" href="#challenge1"></a>
 </h3>
 <div class="callout-content">
 <p>Split into two groups.</p>
@@ -492,6 +492,19 @@ <h3 class="callout-title">Challenge<a class="anchor" aria-label="anchor" href="#
 </div>
 </div>
 </div>
+<div id="accordionSolution1" class="accordion challenge-accordion accordion-flush">
+<div class="accordion-item">
+<button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution1" aria-expanded="false" aria-controls="collapseSolution1">
+  <h4 class="accordion-header" id="headingSolution1">Show me the solution</h4>
+</button>
+<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div class="accordion-body">
+<p>Once you’ve completed one group activity then switch to the next
+group!</p>
+</div>
+</div>
+</div>
+</div>
 <div id="keypoints1" class="callout keypoints">
 <div class="callout-square">
 <i class="callout-icon" data-feather="key"></i>
diff --git a/aio.html b/aio.html
index 4d89efb..b7d522e 100644
--- a/aio.html
+++ b/aio.html
@@ -460,7 +460,7 @@ <h3 class="callout-title">Getting around in BitCurator<a class="anchor" aria-lab
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution1" aria-expanded="false" aria-controls="collapseSolution1">
   <h4 class="accordion-header" id="headingSolution1">Show me the solution</h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
 <div class="accordion-body">
 <p>Getting around: Answers will vary, depending on what you choose to
 look at. At minimum, you should look at the various “Applications” (menu
@@ -740,12 +740,12 @@ <h3 id="mount-disk-image-using-bitcurator-mounter">Mount disk image: Using BitCu
 </section><section id="activities"><h2 class="section-heading">Activities<a class="anchor" aria-label="anchor" href="#activities"></a>
 </h2>
 <hr class="half-width">
-<div id="discussion1" class="callout discussion">
+<div id="challenge1" class="callout challenge">
 <div class="callout-square">
-<i class="callout-icon" data-feather="message-circle"></i>
+<i class="callout-icon" data-feather="zap"></i>
 </div>
 <div class="callout-inner">
-<h3 class="callout-title">Challenge<a class="anchor" aria-label="anchor" href="#discussion1"></a>
+<h3 class="callout-title">Challenge<a class="anchor" aria-label="anchor" href="#challenge1"></a>
 </h3>
 <div class="callout-content">
 <p>Split into two groups.</p>
@@ -757,6 +757,19 @@ <h3 class="callout-title">Challenge<a class="anchor" aria-label="anchor" href="#
 </div>
 </div>
 </div>
+<div id="accordionSolution1" class="accordion challenge-accordion accordion-flush">
+<div class="accordion-item">
+<button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution1" aria-expanded="false" aria-controls="collapseSolution1">
+  <h4 class="accordion-header" id="headingSolution1">Show me the solution</h4>
+</button>
+<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div class="accordion-body">
+<p>Once you’ve completed one group activity then switch to the next
+group!</p>
+</div>
+</div>
+</div>
+</div>
 <div id="keypoints1" class="callout keypoints">
 <div class="callout-square">
 <i class="callout-icon" data-feather="key"></i>
diff --git a/instructor/02-getting-started-bit-curator.html b/instructor/02-getting-started-bit-curator.html
index 2cbfe3c..a701f5e 100644
--- a/instructor/02-getting-started-bit-curator.html
+++ b/instructor/02-getting-started-bit-curator.html
@@ -335,7 +335,7 @@ <h3 class="callout-title">Getting around in BitCurator<a class="anchor" aria-lab
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution1" aria-expanded="false" aria-controls="collapseSolution1">
   <h4 class="accordion-header" id="headingSolution1">Show me the solution</h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
 <div class="accordion-body">
 <p>Getting around: Answers will vary, depending on what you choose to
 look at. At minimum, you should look at the various “Applications” (menu
diff --git a/instructor/03-imaging.html b/instructor/03-imaging.html
index 1761d7e..593c334 100644
--- a/instructor/03-imaging.html
+++ b/instructor/03-imaging.html
@@ -477,12 +477,12 @@ <h3 id="mount-disk-image-using-bitcurator-mounter">Mount disk image: Using BitCu
 </div>
 </section><section id="activities"><h2 class="section-heading">Activities<a class="anchor" aria-label="anchor" href="#activities"></a>
 </h2>
-<hr class="half-width"><div id="discussion1" class="callout discussion">
+<hr class="half-width"><div id="challenge1" class="callout challenge">
 <div class="callout-square">
-<i class="callout-icon" data-feather="message-circle"></i>
+<i class="callout-icon" data-feather="zap"></i>
 </div>
 <div class="callout-inner">
-<h3 class="callout-title">Challenge<a class="anchor" aria-label="anchor" href="#discussion1"></a>
+<h3 class="callout-title">Challenge<a class="anchor" aria-label="anchor" href="#challenge1"></a>
 </h3>
 <div class="callout-content">
 <p>Split into two groups.</p>
@@ -494,6 +494,19 @@ <h3 class="callout-title">Challenge<a class="anchor" aria-label="anchor" href="#
 </div>
 </div>
 </div>
+<div id="accordionSolution1" class="accordion challenge-accordion accordion-flush">
+<div class="accordion-item">
+<button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution1" aria-expanded="false" aria-controls="collapseSolution1">
+  <h4 class="accordion-header" id="headingSolution1">Show me the solution</h4>
+</button>
+<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div class="accordion-body">
+<p>Once you’ve completed one group activity then switch to the next
+group!</p>
+</div>
+</div>
+</div>
+</div>
 <div id="keypoints1" class="callout keypoints">
 <div class="callout-square">
 <i class="callout-icon" data-feather="key"></i>
diff --git a/instructor/aio.html b/instructor/aio.html
index c487161..c0cb274 100644
--- a/instructor/aio.html
+++ b/instructor/aio.html
@@ -465,7 +465,7 @@ <h3 class="callout-title">Getting around in BitCurator<a class="anchor" aria-lab
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution1" aria-expanded="false" aria-controls="collapseSolution1">
   <h4 class="accordion-header" id="headingSolution1">Show me the solution</h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
 <div class="accordion-body">
 <p>Getting around: Answers will vary, depending on what you choose to
 look at. At minimum, you should look at the various “Applications” (menu
@@ -746,12 +746,12 @@ <h3 id="mount-disk-image-using-bitcurator-mounter">Mount disk image: Using BitCu
 </section><section id="activities"><h2 class="section-heading">Activities<a class="anchor" aria-label="anchor" href="#activities"></a>
 </h2>
 <hr class="half-width">
-<div id="discussion1" class="callout discussion">
+<div id="challenge1" class="callout challenge">
 <div class="callout-square">
-<i class="callout-icon" data-feather="message-circle"></i>
+<i class="callout-icon" data-feather="zap"></i>
 </div>
 <div class="callout-inner">
-<h3 class="callout-title">Challenge<a class="anchor" aria-label="anchor" href="#discussion1"></a>
+<h3 class="callout-title">Challenge<a class="anchor" aria-label="anchor" href="#challenge1"></a>
 </h3>
 <div class="callout-content">
 <p>Split into two groups.</p>
@@ -763,6 +763,19 @@ <h3 class="callout-title">Challenge<a class="anchor" aria-label="anchor" href="#
 </div>
 </div>
 </div>
+<div id="accordionSolution1" class="accordion challenge-accordion accordion-flush">
+<div class="accordion-item">
+<button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution1" aria-expanded="false" aria-controls="collapseSolution1">
+  <h4 class="accordion-header" id="headingSolution1">Show me the solution</h4>
+</button>
+<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div class="accordion-body">
+<p>Once you’ve completed one group activity then switch to the next
+group!</p>
+</div>
+</div>
+</div>
+</div>
 <div id="keypoints1" class="callout keypoints">
 <div class="callout-square">
 <i class="callout-icon" data-feather="key"></i>
diff --git a/md5sum.txt b/md5sum.txt
index 0ab6d74..f548000 100644
--- a/md5sum.txt
+++ b/md5sum.txt
@@ -7,7 +7,7 @@
 "episodes/00-intro-prep-setup.md" "a3a5ffed2cef4015091a282bc0f96243" "site/built/00-intro-prep-setup.md" "2024-04-24"
 "episodes/01-digital-forensics-for-archives.md" "81b92bcf462c370cbf354c84e7949443" "site/built/01-digital-forensics-for-archives.md" "2024-04-03"
 "episodes/02-getting-started-bit-curator.md" "599855f98566c606e00981af948f0fd8" "site/built/02-getting-started-bit-curator.md" "2024-04-04"
-"episodes/03-imaging.md" "6c093d1f6b4fbcf2dd14f54a6dd08619" "site/built/03-imaging.md" "2024-04-24"
+"episodes/03-imaging.md" "4497ca25c400a0636e848bd2e078ab60" "site/built/03-imaging.md" "2024-04-24"
 "episodes/04-reporting.md" "ba35b9514f02cce44fa0af65e67546a0" "site/built/04-reporting.md" "2024-04-24"
 "instructors/instructor-notes.md" "cae72b6712578d74a49fea7513099f8c" "site/built/instructor-notes.md" "2024-03-12"
 "learners/reference.md" "1c7cc4e229304d9806a13f69ca1b8ba4" "site/built/reference.md" "2024-03-12"
diff --git a/pkgdown.yml b/pkgdown.yml
index a2bed5f..512b15e 100644
--- a/pkgdown.yml
+++ b/pkgdown.yml
@@ -2,5 +2,5 @@ pandoc: 3.1.11
 pkgdown: 2.0.9
 pkgdown_sha: ~
 articles: {}
-last_built: 2024-04-24T17:47Z
+last_built: 2024-04-24T20:08Z