diff --git a/examples/rtt_timing.rs b/examples/rtt_timing.rs
index 4ee67756ac0d8fceb17692d8701abfa5df55fba9..72fbb09d39f1253d554f1e86e53a1fd5c49575e7 100644
--- a/examples/rtt_timing.rs
+++ b/examples/rtt_timing.rs
@@ -60,37 +60,57 @@ fn timed_loop() -> (u32, u32) {
 // ------------------------------------------------------------------------
 // Exercises:
 //
+// start 2987, end 4793139, diff 4790152
+//
 // A.1) What is the cycle count for the loop?
 // > cargo run --example rtt_timing
 //
 // [Your answer here]
+// 2987
 //
 // A.2) How many cycles per iteration?
 //
 // [Your answer here]
+// 4790152
 //
 // A.3) Why do we need a wrapping subtraction?
 //
 // [Your answer here]
+// If end value has wrapped around then start > end. Thus we need to wrap around when we subtract so we get the correct difference value.
 //
 // ------------------------------------------------------------------------
 // Now try a release (optimized build, see `Cargo.toml` for build options).
 // B.1) What is the cycle count for the loop?
 // > cargo run --example rtt_timing --release
 //
+// start 30305915, end 30375916, diff 70001
+//
 // [Your answer here]
+// 30305915
 //
 // B.2) How many cycles per iteration?
 //
 // [Your answer here]
+// 70001
 //
 // What is the speedup (A/B)?
 //
 // [Your answer here]
+// 4790152 / 70001 = 68.4297652891
+// 
 //
 // Why do you think it differs that much?
 //
 // [Your answer here]
+// I think that the optimizer removed the for loop:
+//      for _ in 0..10000 {
+//          asm::nop();
+//      }
+// Thus the end variable is set right after the start variable. This makes the time difference very
+// small. But it is not near 10000 time faster because the function DWT::get_cycle_count() is much
+// slower at getting the cycle count then it is to run one iteration of the loop.
+//
+//
 //
 // ------------------------------------------------------------------------
 // In the loop there is just a single assembly instruction (nop).
@@ -112,15 +132,20 @@ fn timed_loop() -> (u32, u32) {
 // C.1) What is the cycle count for the loop?
 // > cargo run --example rtt_timing --release --features nightly
 //
+// start 1356808538, end 1356848539, diff 40001
+//
 // [Your answer here]
+// 1356808538
 //
 // C.2) How many cycles per iteration?
 //
 // [Your answer here]
+// 40001
 //
 // What is the speedup (A/C)?
 //
 // [Your answer here]
+// 4790152 / 40001 = 119.75080623
 //
 // ------------------------------------------------------------------------
 // D) Now lets have a closer look at the generated assembly.