PSLE Eight pupils shared the cost of a present equally. When calculating the amount for each share, one of the pupils made a mistake by dividing the cost of the present by 7 instead of 8. Each pupil paid $4.20 more than his share. What should be the cost of the present?
|
8 pupils |
7 pupils |
Number |
8 |
7 |
Value |
1 u |
1 u + 4.20 |
Total value |
8 u |
7 u + 29.40 |
Cost of the present if shared by 8 pupils
= 8 x 1 u
= 8 u
Cost of the present if shared by 7 pupils
= 7 x (1 u + 4.20)
= 7 u + 29.40
The total amount that the 8 pupils shared is the same as the total amount that the 7 pupils shared.
8 u = 7 u + 29.40
8 u - 7 u = 29.40
1 u = 29.40
Cost of the present
= 8 u
= 8 x 29.40
= $235.20
Answer(s): $235.20