The average age of a group is increased by 4 years when a person of whose age is 32 years was replaced by a person whose age is 56. Find the number of people in the group.
Answer & explanation
Correct answer: option 1
Lets assume number of people in the group be x and the average be y
x(y + 4) = xy - 32 + 56
⇒ xy + 4x = xy + 24
⇒ 4x = 24
⇒ x = 6