Question

4 year ago the average age of Aand B was 18 year. Now, the average age of A,B and C is 24 year. After 8 year age of c will be​

Answer 1

Answer:

36 year

Step-by-step explanation:

Let the present age of A be a year and age of B be b year.

  Age before 4 year :

       A = a - 4 year

       B = b - 4 year

That time average of ages was 18 year :

⇒ 18 = ( age of A + age of B ) / 2

⇒ 18*2 = ( a - 4 + b - 4 )

⇒ 36 = ( a + b - 8 )

⇒ 36 + 8 = a + b

⇒ 44 = a + b

Now, present age of A is a and that of B is b.

    sum of ages is a + b = 44 (from above)

now, average of ages of A, B and C is 24 :

⇒ 24 = ( age of A + age of B + age of C ) / 3

⇒ 24*3 = ( a + b + age of C )

⇒ 72 = ( 44 + age of C )

⇒ 72 - 44 = age of C

⇒ 28 = age of C

    After 8 years :

           age of C = 28 + 8

            ⇒ 36 year

Answer 2

Answer:

36

Step-by-step explanation:

Let's take A's age as A, B's age as B and C's age as C.

Equation 1:

((A-4)+(B-4))/2 = 18

A+B = 44 ---(1)

Equation 2:

(A+B+C)/3 =24

substituting value of equation 1 in equation 2

(44+C)/3 =24

C=28

After 8 years of age C will be 28+8 = 36