F.4 MATHS

Themembers of the science club plan to have a trip. The total expenses is$9000,which is to be shared equally among the members. however, three of themwithdraw just before the trip, and each of other members has to pay $150 more. howmany members are there in the science club?

Let n be the number of members.

[9000 / (n - 3)] - [9000 / n] = 150
[9000n / n(n - 3)] - [9000(n - 3) / n(n - 3)] = 150
9000n - 9000(n - 3) = 150n(n - 3)
9000n - 9000n + 27000 = 150n² - 450n
150n² - 450n - 27000 = 0
n² - 3n + 180 = 0
(n - 15)(n + 12) = 0
n = 15 or n = -12 (rejected)

Hence, there are 15 members in thescience club.