Question 1

Fred     [—-u—-][12]

Fiona   [—-u—-]

(2/3)(u+12) = u + 5           —–> x 3 on both sides

2u + 24 = 3u + 15

3u-2u = 24-15

u = 9

Therefore, Fiona is 9 years old.

Question 2

T + J = 475

B + T = 247                   

J – B =  228                 (Minus the  2 equations)

B  [u][u]<–228–>

J   [u][u][u][u][u]

3u = 228  => u = 76 

B = 2u = 152    => T = 247-152 = 95

Therefore,  Ben has 152-95= 57 more marbles than Tom.

Thank you sushi88!

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