In a mall, some water guns and rubber balls were on sale.
14 of the items were water guns.
23 of the water guns and 130 rubber balls were sold. There were
19 of the items left in the mall. How many water guns and rubber balls were there in the mall at first?
|
Water guns |
Rubber balls |
Total |
Comparing water guns and rubber balls at first |
1x9 = 9 u |
3x9 = 27 u |
4x9 = 36 u |
Before |
3x3 = 9 u |
|
9x4 = 36 u |
Change |
- 2x3 = - 6 u |
- 130
|
- 8x4 = - 32 u |
After |
1x3 = 3 u |
1 u |
1x4 = 4 u |
The total number of toys at first is repeated. Make the total number of toys at first the same. LCM of 4 and 9 is 36.
The number of water guns at first is repeated. Make the number of water guns the same. LCM of 9 and 3 is 9.
Number of rubber balls left
= 4 u - 3 u
= 1 u
Number of rubber balls sold
= 27 u - 1 u
= 26 u
26 u = 130
1 u = 130 ÷ 26 = 5
Number of water guns and rubber balls at first
= 36 u
= 36 x 5
= 180
Answer(s): 180