Ivan, Vincent, Owen and Mark bought a laptop for their aunt. Ivan paid
13 of what the rest paid. Vincent paid
15 of what the rest paid. Owen paid
16 of what the rest paid. Mark paid $128 more than Ivan. How much did the laptop cost?
| Ivan |
Vincent |
Owen |
Mark |
Total |
| 1x21 |
|
|
|
4x21 |
| |
1x14 |
|
|
6x14 |
| |
|
1x12 |
|
7x12 |
| 21 u |
14 u |
12 u |
37 u |
84 u |
The cost of the laptop is repeated. Make the cost of the laptop the same. LCM of 4, 6 and 7 is 84.
Amount that Mark had
= 84 u - (21 u + 14 u + 12 u)
= 37 u
Amount that Mark paid more than Ivan
= 37 u - 21 u
= 16 u
16 u = 128
1 u = 128 ÷ 16 = 8
Cost of the laptop
= 84 u
= 84 x 8
= $672
Answer(s): $672
