diff --git a/1-4-scalability.md b/1-4-scalability.md
index 31969bc..62fef31 100644
--- a/1-4-scalability.md
+++ b/1-4-scalability.md
@@ -58,7 +58,7 @@
 
 - formula
     - Speedup factor:
-      $$S = T / (\alpha \times T + (1 - \alpha \times T / n)) = 1 / (\alpha + (1 - \alpha) / n)$$
+      $$S = T / (\alpha \times T + (1 - \alpha) \times T / n) = 1 / (\alpha + (1 - \alpha) / n)$$
     - $\alpha$: fraction of serial computation
     - 1 - alpha: part that can be parallelized
     - $n$: processors used
diff --git a/2-2-cuda.md b/2-2-cuda.md
index b4311de..0812f82 100644
--- a/2-2-cuda.md
+++ b/2-2-cuda.md
@@ -44,7 +44,7 @@
     ```
 - Note to self: run `nvcc` with `-arch=native` otherwise it won't work.
 
-### Device code and Host code
+### Device code and Host code (Important)
 
 - Compiler `nvcc` separates source code into host and device code
     - Device code (kernels): definition marked with `__global__`, called from
diff --git a/assets/code/a.out b/assets/code/a.out
deleted file mode 100755
index 10f82e0..0000000
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