diff --git a/src/borrowing/exercise.md b/src/borrowing/exercise.md
index ada1091f1334..a6b9cd3a2e88 100644
--- a/src/borrowing/exercise.md
+++ b/src/borrowing/exercise.md
@@ -1,5 +1,5 @@
 ---
-minutes: 30
+minutes: 20
 ---
 
 # Exercise: Health Statistics
diff --git a/src/control-flow-basics/exercise.md b/src/control-flow-basics/exercise.md
index 064a20f710f0..6f7df66ddd57 100644
--- a/src/control-flow-basics/exercise.md
+++ b/src/control-flow-basics/exercise.md
@@ -1,5 +1,5 @@
 ---
-minutes: 30
+minutes: 15
 ---
 
 # Exercise: Collatz Sequence
diff --git a/src/error-handling/exercise.md b/src/error-handling/exercise.md
index 4a4860838a49..0da3810622e7 100644
--- a/src/error-handling/exercise.md
+++ b/src/error-handling/exercise.md
@@ -1,5 +1,5 @@
 ---
-minutes: 20
+minutes: 30
 ---
 
 # Exercise: Rewriting with Result
diff --git a/src/references/exercise.md b/src/references/exercise.md
index 6bad4bd78365..5374fb85d24e 100644
--- a/src/references/exercise.md
+++ b/src/references/exercise.md
@@ -1,5 +1,5 @@
 ---
-minutes: 30
+minutes: 15
 ---
 
 # Exercise: Geometry
diff --git a/src/std-types/exercise.md b/src/std-types/exercise.md
index ac41036f68e1..efe030933bd2 100644
--- a/src/std-types/exercise.md
+++ b/src/std-types/exercise.md
@@ -1,5 +1,5 @@
 ---
-minutes: 10
+minutes: 20
 ---
 
 # Exercise: Counter
diff --git a/src/tuples-and-arrays/exercise.md b/src/tuples-and-arrays/exercise.md
index 1094942f6f5d..c03c10fc7185 100644
--- a/src/tuples-and-arrays/exercise.md
+++ b/src/tuples-and-arrays/exercise.md
@@ -1,5 +1,5 @@
 ---
-minutes: 30
+minutes: 15
 ---
 
 # Exercise: Nested Arrays
diff --git a/src/types-and-values/exercise.md b/src/types-and-values/exercise.md
index 76abd8302f5e..1512208b41b5 100644
--- a/src/types-and-values/exercise.md
+++ b/src/types-and-values/exercise.md
@@ -1,5 +1,5 @@
 ---
-minutes: 30
+minutes: 15
 ---
 
 # Exercise: Fibonacci