Olivia spent
23 of her money on 12 pencils and 6 files. The cost of each file is 3 times the cost of each pencil. She bought some more pencils with
23 of her remaining money. How many pencils did Olivia buy altogether?
| 12 pencils + 6 files |
Remaining
amount |
Total
amount |
| 2 p = 30 u |
1 p = 15 u |
3 p |
12
pencils |
6
files |
More pencils |
Left |
|
| |
|
2 |
1 |
|
| 12 u |
18 u |
10 u |
|
|
Cost of 1 pencil = 1 u
Cost of 1 file = 3 u
Cost of 12 pencils = 12 x 1 u = 12 u
Cost of 6 files = 6 x 3 u = 18 u
Cost of 12 pencils + 6 files
= 12 u + 18 u
= 30 u
2 p = 30 u
1 p = 30 u ÷ 2 = 15 u
Amount of remaining money that Olivia spent on buying more pencils
=
23 x 15 u
= 10 u
Number of pencils that Olivia bought with
23 of her remaining money
= 10 u ÷ 1 u
= 10
Total number of pencils that Olivia bought
= 12 + 10
= 22
Answer(s): 22
