diff --git a/exercises/_13-sa-foundations-mathematical.qmd b/exercises/_13-sa-foundations-mathematical.qmd
index 6dd5a725..13daf8fa 100644
--- a/exercises/_13-sa-foundations-mathematical.qmd
+++ b/exercises/_13-sa-foundations-mathematical.qmd
@@ -1,4 +1,4 @@
-1.  \(a\) `r pnorm(-1.35, mean = 0, sd = 1)` (b) `r 1 - pnorm(1.48, mean = 0, sd = 1)` (c) `r pnorm(1.5, mean = 0, sd = 1) - pnorm(-0.4, mean = 0, sd = 1)` (d) $P(|Z| > 2) = P(Z < -2) + P(Z > 2)$ `r pnorm(-2, mean = 0, sd = 1) + 1 - pnorm(2, mean = 0, sd = 1)`
+1.  \(a\) `r pnorm(-1.35, mean = 0, sd = 1)` (b) `r 1 - pnorm(1.48, mean = 0, sd = 1)` (c) `r pnorm(1.5, mean = 0, sd = 1) - pnorm(-0.4, mean = 0, sd = 1)` (d) $P(|Z| > 2) = P(Z < -2) + P(Z > 2)$ `r pnorm(-2, mean = 0, sd = 1) + 1 - pnorm(2, mean = 0, sd = 1)`.
 \addtocounter{enumi}{1}
 
 1.  \(a\) Verbal: $N(\mu = 151, \sigma = 7)$, Quant: $N(\mu = 153, \sigma = 7.67)$. (b) $Z_{VR} = 1.29$, $Z_{QR} = 0.52$. (c) She scored 1.29 standard deviations above the mean on the Verbal  Reasoning section and 0.52 standard deviations above the mean on the Quantitative Reasoning section.