Question

19. One year ago, A was four times as old as B. After 6
years, A will be 9 years older than B. Find the ratio of
their present ages?​

Answer 1

Solution

Given:-

• One year ago, A was four times as old as B.
• After 6 years, A will be 9 years older than B.

Find :-

• Ratio of thier present age.

Explanation

Let,

• Present age of A = x years
• Present age of B = y years

Case 1

==> (x - 1) = 4×(y-1)

==> x - 5y = -4 + 1

==> x - 5y = -3_______________(1)

Case 2.

==> (x+6) = 9+(y+6)

==> x - y = 15 - 6

==> x -y = 9 _______________(2)

Sub equ(1) & equ(2)

==> -5y + y = -3 -9

==> -4y = -12

==> y = -12/(-4)

==> y = 3

Keep Value of y in equ(2)

==> x - 3 = 9

==> x = 9 + 3

==> x = 12

Hence

• present age of A = 12 years
• Present age of B = 3 years

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