Question

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

Answer 1

48

Explanation:

L = D + 28

⅓L = ⅘D

Solve the system of equations using elimination or substitution. Using substitution:

⅓L = ⅘(L − 28)

Multiply both sides by 15:

5L = 12(L − 28)

Distribute:

5L = 12L − 336

Combine like terms:

336 = 7L

Divide:

L = 48