Question

in 10 years Charlie will be 4/3 as old as Doug. In 5 years Doug will be 5/7 as old as Charlie. What is the present age of each?

Answer 1

Answer:

Charlie's age is 30yrs

Doug,'s age is 20yrs

Step-by-step explanation:

Let Charlie's present age be x and Doug's present age be y

ATQ

x + y = 4/3 (y + 10)

3x + 30 = 4y + 40

3x - 4y = 10 —(I)

Also

y + 5 = 5/7 (x+5)

7y + 35 = 5x +25

5x - 7y =10 —(II)

Multiply (I) with 5 and (II) with 3 and subtract them

15x - 20y = 50

15x - 21y = 30

– + –

————————

y = 20

Substituting in (I)

3x - 4(20) = 10

3x = 10+ 80

3x = 90

x = 30

—> Charlie's age is 30 while Doug's age is 20