Question

after 5 years age of A become 3 times of B's Age. 5 years ago, age of A was 7 time of B's age. find the age of a and b?

Answer 1

Case #1:
a+5 = 3(b+5)
a-3b = 10

Case #2:
a-5 = 7(b-5)
a-7b = -30

Solving the two equations,
a = 40
b = 10

Answer 2

Hi friend,

Let the present age of A and B be X and Y year's.

After 5 years age of A = (X+5) years.

After 5 years age of B= (Y+5) years.

According to question,

(X+5) = 3(Y+5)

X+5 = 3Y +15

X-3Y = 15-5

X-3Y = 10......(1)

Again,

5 years before age of B = (Y-5) years.

5 years before Age of A = (X-5) years.

According to question,

(X-5) = 7(Y-5)

X -5 = 7Y -35

X -7Y = -35+5

X -7Y = -30......(2)

From equation (1) we get

X-3Y = 10

X = 10+3Y.......(3)

Putting the value of X in equation (2)

X -7Y = -35

(10+3Y) -7Y = -30

-4Y = -3-10

-4Y = -40

Y = -40/-4 = 10

Putting the value of Y in equation (3)

X = 10+3Y = 10 + 3 × 10 = 10+30 = 40

present Age of B = Y = 10 years.

Present age of A = X = 40 years


HOPE IT WILL HELP YOU.... :-)