Question

Leah has 28 more marbles than Dan. One third of Leah’s marbles is equal to 4/5 of Dan’s marbles. Find how many marbles does Leah have?

Answer 1

Answer

Let L = Leah's marble count; D = Dan's marble count

L = D + 28

and

1/3 L = 4/5 D

At this point you have a choice of how to proceed. Let's replace L in the 2nd equation with D + 28.

1/3 (D + 28) = 4/5 D

Multiply both sides by 15 to eliminate the fractions.

5(D+28) = 12D

5D + 140 = 12D

7D = 140

D = 20; L is 28 more than 20, so L=48.