In a store, some water guns and toy masks were on sale.
15 of the items were water guns.
13 of the water guns and 69 toy masks were sold. There were
16 of the items left in the store. How many water guns and toy masks were there in the store at first?
| |
Water guns |
Toy masks |
Total |
Comparing water guns
and toy masks at first |
1x6 =
6 u |
4x6 =
24 u |
5x6 =
30 u |
| Before |
3x2 =
6 u |
|
6x5 =
30 u |
| Change |
- 1x2 =
- 2 u |
- 69
|
- 5x5 =
- 25 u |
| After |
2x2 =
4 u |
1 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 water guns at first is repeated. Make the number of water guns the same. LCM of 6 and 3 is 6.
Number of toy masks left
= 5 u - 4 u
= 1 u
Number of toy masks sold
= 24 u - 1 u
= 23 u
23 u = 69
1 u = 69 ÷ 23 = 3
Number of water guns and toy masks at first
= 30 u
= 30 x 3
= 90
Answer(s): 90
