Question

The Price of a commodity increased by 8% from 1978-79, 12.5% from 1979-80 and 77% from 1980-81. What is the average increase from 1978-79 to 1980-81?

Answer 1

Avginc= (8+12.5+77)/3

Answer 2

Given :-

• The Price of a commodity increased by 8% from 1978-79.
• 12.5% from 1979-80 .
• 77% from 1980-81.

To Find :-

• What is the average increase from 1978-79 to 1980-81 ?

Solution :-

Let us Assume that, Initial Price of commodity was Rs.100 in 1978.

Than,

→ Price of commodity at the end of 1980 = initial Price * (100 + R1/100) * (100 + R2/100) * (100 + R3/100)

we have given that,

• R1 = 8% .
• R2 = 12.5% .
• R3 = 77% .
• initial Price = Rs.100 (Let.)

Putting all values Now, we get,

→ Final Price = 100 * (100 + 8)/100 * (100 + 12.5)/100 + (100 + 77)/100

→ Final Price = 100 * (108/100) * (112.5/100) * (177/100)

→ Final Price = (108 * 1125 * 177) / (10 * 100 * 100)

→ Final Price = (21505500) / (100000)

→ Final Price = 215.055 = Rs.215.06

So,

→ Total Price increase from 1978 to 1980 = 215.06 - 100 = Rs.115.06 .

Than,

→ increase Price in % = (115.96 * 100)/100 = 115.06%

Therefore,

→ The average increase from 1978-79 to 1980-81 = (115.06) / 3 = 38.35% (Ans.)

Hence, the average increase from 1978-79 to 1980-81 is 38.35% .