Bill is now 100% older then his younger sister Rebecca

In 8 years he will be 20% older

How old is Rebecca now?

Rachella333 Feb 12, 2016

#1**+5 **

Best Answer

Rebecca's age = x Bill's age = 2x 2x + 8 = 1.2(x+8)

.8x = 1.6

x = 1.6/.8=2 Bill is 4 Rebecca is 2

Guest Feb 12, 2016

#2**+5 **

100% older means twice as old

20% older means 6/5 as old

Let Rebecca's current age = x so....Bill's = 2x

In 8 years we have........his age = 6/5 her age

2x + 8 = (6/5) [ x + 8] simplify

2x + 8 = (6/5)x + 48/5

2x + 8 = (6/5)x + 48/5 subtract 8, (6/5)x from both sides

2x - (6/5)x = 48/5 - 8

(4/5)x = 8/5 multiply through by 5

4x = 8 divide both sides by 4

x = 2 this is Rebecca's current age.......so Bill = 2x =4

And...in 8 years, Rebecca will be 10 and Bill will be 12 .....and 12 is 6/5 of 10 → 20% more than 10

CPhill Feb 12, 2016