Answer:
she sold 8 oatmeal cookies
total = 72+8=80 cookies sold
Explanation:
72 at a 9:1 ratio, would be 72:8
so she sold 8 oatmeal cookies
total = 72+8=80 cookies sold
Further explanation:
for every 9 PB cookies she sold, she sold one OM cookie.
She sold 72 PB cookies, so she sold 8 OM cookies because 72/9=8.