Answer:
1 cookie
Explanation:
75% = 75/100
75 and 100 are both divisible by 25, therfore the simplified verision is 3/4
in order to get 100% we would need to:
3/4 + num of cookies = 4/4
re-arranged by subtracting 3/4 on bith sides:
num of cookie = 4/4 - 3/4
num of cookie = 1/4
meaning 1/4 of her orders is cookies