Question

the sum of present ages of ria and abby is 48 years. today abby is 4 years older than shweta. the respective ratio of the present ages of ria and shweta is 4: 7. what was abby's age two years ago?

Answer 1

30 years then.

Explanation:

Let the present age of Ria be x and Abby be y, and of Sweta be z.

Then, according to the question,

• x + y = 48 ..1

Today, Abby is 4 yrs older than Sweta,i.e.,

• y = 4+z.(2)

Also, ratio of present ages of Ria:Sweta

• x:z = 4:7
• x/z = 4/7
• 4z = 7x..(3)

Putting the value of y from eqn (2) to eqn 1,

• x + 4 + z = 48
• x + z = 44( eqn : 4)

From eqn (3),

• 4z = 7x
• x = 4z/7(eqn:5)

Putting the value of x in eqn (4),

• 4z/7 + z = 44
• 11z/7 = 44
• z = 4*7 = 28

From eqn 5, putting the value of z in it,

• x = 4*28/7
• x = 4*4 = 16

Putting the value of x in eqn 1,

• x+y = 48
• y = 48 -16 =32

We have to find the age of Abby two years ago, i.e. 32-2 = 30 years old then back.