Candy Collected Part 1... If Lucy got 5/20 of what Conner got, that means she got 25/100 pieces of candy. Amy got 1/10 less than Lucy, which means she got 15/100 pieces.
Candy Collected Part 2... Caleb got 3x more than Amy, which means Caleb has 45/100 pieces. Mary got 3x less of what Caleb got, which means she got 15/100 pieces of candy. 15/100 converted to decimal form is 0.15