Min spent
35 of her money on 4 pencils and 7 pens. The cost of one pen was twice the cost of one pencil. She bought some more pens with
16 of her remaining money. How many pens did Min buy altogether?
4 pencils and
7 pens |
Remaining amount |
| 3x3 |
2x3 |
| |
More pens |
Left |
| |
1x1 |
5x1 |
| 9 p |
1 p |
5 p |
Cost of 1 pencil = 1 u
Cost of 1 pen = 2 u
Cost of 4 pencils = 4 x 1 u = 4 u
Cost of 7 pens = 7 x 2 u = 14 u
Total cost of 4 pencils and 7 pens
= 4 u + 14 u
= 18 u
9 p = 18 u
1 p = 18 ÷ 9 = 2 u
Amount that Min used to buy more pens
= 1 p
= 1 x 2 u
= 2 u
Number of more pens that Min bought
= 2 u ÷ 2 u
= 1
Total number of pens that Min bought
= 7 + 1
= 8
Answer(s): 8
