In a group of 135 persons, 50% people contributed tk. 40 each, 30% contributed Tk. 60 each and the remaining persons contributed Tk. 80. Find the average contribution for the group?
A Tk. 50
B Tk. 54
C Tk. 60
D Tk. 62
Solution
Correct Answer: Option B
total people = 135
Since
50% of them contributed Tk. 40
∴ amount contributed by these 50% = (135/2) × 40 = 2700
Since 30% of them contributed TK. 60
∴ amount contributed by these 30% = (30/100) × (135) × 60 = 2430
and
remaining 20% of them contributed Tk. 80
∴ amount contributed by these 20% = (20/100) × 135 × 80 = 2160
∴ Total amount contributed = 2700 + 2430 + 2160 = 7290
∴ Average contribution = 7290/135 = 54