Question

b) The total of the ages of A, B and C is 80 years. What was the total of their ages three years ago?​

Answer 1

Answer:

71 years

Step-by-step explanation:

Required sum = (80 - 3 x 3) years = (80 - 9) years = 71 years.

Answer 2

Answer:

he total of their ages three years ago was 71 years

Step-by-step explanation:

Let us assume that,

→ Present age of A = a years

→ Present age of B = b years

→ Present age of C = c years

so,

→ Total ages of (A + B + C) = 80 years

→ (a + b + c) = 80 --------- Eqn.(1)

now,

→ Age of A three years ago = Present age - 3 = (a - 3) years

→ Age of B three years ago = Present age - 3 = (b - 3) years

→ Age of C three years ago = Present age - 3 = (b - 3) years

then,

→ Total ages of (A + B + C) three years ago = (a - 3) + (b - 3) + (c - 3) = a + b + c - 3 - 3 - 3 = (a + b + c) - 9 -------- Eqn.(2)

putting value of Eqn.(1) in Eqn.(2) we get,

→ Total ages of (A + B + C) three years ago = 80 - 9 = 71 years (Ans.)

∴, the total of their ages three years ago was 71 years