Question

The average age of four members of a
family is 20 years. If the age of the
grandfather be included, the average is
increased by 9 years. What it the age of
the grandfather?​

Answer 1

Answer:

45 years

Step-by-step explanation:

sum =average * number of members

sum = 20 * 4

= 80

when grandfather's age was added the average was increased by 9 years

means 20 +9 = 29 years and no of members has become 5

So, sum =29 * 5

= 125

Age of grandfather= 125 - 80

= 45