Amanda used 15%
Rose used 0.17
Multiply the decimal by 100 to get the percentage:
0.17 x 100 = 17%
Hannah used 16/25
Divide 16 by 25 to get a decimal then multiply by 100 to get the percentage:
16/25 = 0.64 x 100 = 64%
64% is greater than 15% and 17% so Hannah used the most.