Thread: Age Problem

The sums of the ages of grandpa, dad and my brother is 85. Three years ago, grandpa was twice as old as dad. Four years from now, dad will be fours times as old as my brother. How old are they now?

Thanks.

Hi,

G = grandpa's age
D = dad's age
B = brother's age

G + D + B = 85
G - 3 = 2*(D - 3)
D + 4 = 4*(B + 4)

Three equations with three variables. Can you do the next step?

Originally Posted by reiward

The sums of the ages of grandpa, dad and my brother is 85. Three years ago, grandpa was twice as old as dad. Four years from now, dad will be fours times as old as my brother. How old are they now?

Thanks.

Hi reiward,

Let's do it with one equation....for fun.

Let x = dad's age

2(x-3)= grandpa's age -3
2(x-3)+3 = grandpa's age

x + 4 = 4(brother's age +4)
x + 4 = 4 (brother's age) +16
(x - 12)/4 = brother's age

Now, add 'em up.

x + 2(x-3)+3+(x-12)/4 = 85

x + 2x-6+3 + (x-12)/4 = 85

4x + 8x - 12 + x - 12 = 340

13x = 364

x = 28 (Dad's age)

2(x-3)+3 = 2(28-3)+3 = 2(25)+3 = 53 (Grandpa's age)

(x-12)/4 = (28-12)/4 = 16/4 = 4 (Brother's age)