Mr jacob is 55 years old and Tony is 7 years old. In how many years will Mr. Jacob be 4 times as old as Tony?
X = Tony's future age.
4x = Mr. Jacob's future age.
4x - x = 55-7
3x = 48
X = 16
4x = 4 * 16 = 64
16-7 = 9 years.
64-55 = 9 years.
So Mr. Jacobs will be 4 times as old as Tony in 9 years.