Yen spent
23 of her money on 10 staplers and 5 pens. The cost of each pen is 2 times the cost of each stapler. She bought some more staplers with
12 of her remaining money. How many staplers did Yen buy altogether?
| 10 staplers + 5 pens |
Remaining
amount |
Total
amount |
| 2 p = 20 u |
1 p = 10 u |
3 p |
10
staplers |
5
pens |
More staplers |
Left |
|
| |
|
1 |
1 |
|
| 10 u |
10 u |
5 u |
|
|
Cost of 1 stapler = 1 u
Cost of 1 pen = 2 u
Cost of 10 staplers = 10 x 1 u = 10 u
Cost of 5 pens = 5 x 2 u = 10 u
Cost of 10 staplers + 5 pens
= 10 u + 10 u
= 20 u
2 p = 20 u
1 p = 20 u ÷ 2 = 10 u
Amount of remaining money that Yen spent on buying more staplers
=
12 x 10 u
= 5 u
Number of staplers that Yen bought with
12 of her remaining money
= 5 u ÷ 1 u
= 5
Total number of staplers that Yen bought
= 10 + 5
= 15
Answer(s): 15
