Question

Mary and her brother John collect foreign coins. Mary has four times the number of coins that John has. Together they have 200 foreign coins.

Answer 1

x + 4x = 150

5x = 150  

x = 30

John has x = 30 coins

Mary has 4x = 4*30 = 120 coins.Let the number of coins John has be "x".

The the number of coins Mary has is "4x"

Answer 2

John has 40 coin and Mary has 160 coins because 40 times 4 equals 160 and 160 plus 40 equals 200 so Mary has 160 and John has 40