Leah has 28 more marbles than Dan. 1/3 of Leah’s marbles is equal to 4/5 of Dan’s marbles. Find the amount of Leah’s marbles.

Question

I need helpppppp

Answer 1

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.

 

Note: if you have not reached the point where you are using two equations for problems like this then you might start this way.

 

L = Leah's marble count.

L-28 = Dan's marble count.

 

1/3 L = 4/5(L-28)

 

5L = 12(L-28)

 

etc.