In a shop, some toy rifles and dolls were on sale.
110 of the items were toy rifles.
13 of the toy rifles and 231 dolls were sold. There were
19 of the items left in the shop. How many toy rifles and dolls were there in the shop at first?
| |
Toy rifles |
Dolls |
Total |
Comparing toy rifles
and dolls at first |
1x9 =
9 u |
9x9 =
81 u |
10x9 =
90 u |
| Before |
3x3 =
9 u |
|
9x10 =
90 u |
| Change |
- 1x3 =
- 3 u |
- 231
|
- 8x10 =
- 80 u |
| After |
2x3 =
6 u |
4 u |
1x10 =
10 u |
The total number of toys at first is repeated. Make the total number of toys at first the same. LCM of 10 and 9 is 90.
The number of toy rifles at first is repeated. Make the number of toy rifles the same. LCM of 9 and 3 is 9.
Number of dolls left
= 10 u - 6 u
= 4 u
Number of dolls sold
= 81 u - 4 u
= 77 u
77 u = 231
1 u = 231 ÷ 77 = 3
Number of toy rifles and dolls at first
= 90 u
= 90 x 3
= 270
Answer(s): 270
