Gillian spent
34 of her money on 15 pencils and 5 pens. The cost of each pen is 3 times the cost of each pencil. She bought some more pencils with
12 of her remaining money. How many pencils did Gillian buy altogether?
| 15 pencils + 5 pens |
Remaining
amount |
Total
amount |
| 3 p = 30 u |
1 p = 10 u |
4 p |
15
pencils |
5
pens |
More pencils |
Left |
|
| |
|
1 |
1 |
|
| 15 u |
15 u |
5 u |
|
|
Cost of 1 pencil = 1 u
Cost of 1 pen = 3 u
Cost of 15 pencils = 15 x 1 u = 15 u
Cost of 5 pens = 5 x 3 u = 15 u
Cost of 15 pencils + 5 pens
= 15 u + 15 u
= 30 u
3 p = 30 u
1 p = 30 u ÷ 3 = 10 u
Amount of remaining money that Gillian spent on buying more pencils
=
12 x 10 u
= 5 u
Number of pencils that Gillian bought with
12 of her remaining money
= 5 u ÷ 1 u
= 5
Total number of pencils that Gillian bought
= 15 + 5
= 20
Answer(s): 20
