In a mall, some dolls and mini-helicopters were on sale.
15 of the items were dolls.
23 of the dolls and 252 mini-helicopters were sold. There were
16 of the items left in the mall. How many dolls and mini-helicopters were there in the mall at first?
| |
Dolls |
Mini-helicopters |
Total |
Comparing dolls
and mini-helicopters at first |
1x6 =
6 u |
4x6 =
24 u |
5x6 =
30 u |
| Before |
3x2 =
6 u |
|
6x5 =
30 u |
| Change |
- 2x2 =
- 4 u |
- 252
|
- 5x5 =
- 25 u |
| After |
1x2 =
2 u |
3 u |
1x5 =
5 u |
The total number of toys at first is repeated. Make the total number of toys at first the same. LCM of 5 and 6 is 30.
The number of dolls at first is repeated. Make the number of dolls the same. LCM of 6 and 3 is 6.
Number of mini-helicopters left
= 5 u - 2 u
= 3 u
Number of mini-helicopters sold
= 24 u - 3 u
= 21 u
21 u = 252
1 u = 252 ÷ 21 = 12
Number of dolls and mini-helicopters at first
= 30 u
= 30 x 12
= 360
Answer(s): 360
