Three girls gave an equal amount of money to buy a present for Cole. Min used
13 of her money. Jen used
35 of her money and Usha used
45 of hers. They had a total of $639 at first. How much was the present?
|
Min |
Jen |
Usha |
Total |
Before |
3x12 = 36 u |
5x4 = 20 u |
5x3 = 15 u |
71 u ($639) |
Change |
- 1x12 = - 12 u |
- 3x4 = - 12 u |
- 4x3 = - 12 u |
- 36 u |
After |
2x12 = 24 u |
2x4 = 8 u |
1x3 = 3 u |
35 u |
The three girls gave equal amount of money to buy the present. Make the amount that each spent the same. LCM of 1, 3 and 4 is 12.
Total amount that three girls had at first
= 36 u + 20 u + 15 u
= 71 u
71 u = 639
1 u = 639 ÷ 71 = 9
Cost of the present
= 3 x 12 u
= 36 u
= 36 x 9
= $324
Answer(s): $324