Question

8. Ali is six times as old as Rihanna. How old was Ali when Rihanna was born if sum of their ages after 7 years is 49.

Answer 1

Answer: 25

Step-by-step explanation:

Let the age of Ali ad Rihanna be x and y.

We get,

x = 6y                             (1)

x + 7 + y + 7 = 49           (2)

From (2) we get,

x + y + 14 = 49

Subtracting 14 on both sides we get,

x + y + 14 - 14 = 49 - 14

x + y = 35

From (1)

x = 6y

Dividing both sides by 6 we get,

x ÷ 6 = 6y ÷ 6

x ÷ 6 = y

Let us put this value on equation (2)

We get,

x + x/6 = 35

Using cross multiplication we get,

$\frac{6x+x}{6}$ = 35

7x/6 = 35

Multiplying both sides by 6  we get,

7x/6 × 6 = 35 x 6

7x = 35 x 6

Dividing both sides by 7 we get,

7x ÷ 7 = 210 ÷ 7

x = 30

If x = 30 then y = 30 ÷ 6 = 5

So when Rihanna was just born, then Ali's age would be 30 - 5 = 25