Ben and Samuel had the same number of marbles.

Question

Ben and Samuel had the same number of marbles. After Ben gave away 15 marbles and Samuel gave away 35 marbles, Ben has three times as many marbles as Samuel. How many marbles did each of them have at first? 

 

Please tell me the final answer.

Answer 1

Let b = # Ben's marbles

Let s = # Samuel's marbles

 

b = s

b - 15 = 3(s - 35)

 

s-15 = 3s - 105

90 = 2s

45 = s

 

Both started with 45 marbles

 

Check:  45-15=3(45-35)

             30 = 3(10)

             30 = 30

Answer works