Gabby spent
25 of her money on 10 rulers and 7 pens. The cost of one pen was twice the cost of one ruler. She bought some more pens with
16 of her remaining money. How many pens did Gabby buy altogether?
10 rulers and
7 pens |
Remaining amount |
| 2x2 |
3x2 |
| |
More pens |
Left |
| |
1x1 |
5x1 |
| 4 p |
1 p |
5 p |
Cost of 1 ruler = 1 u
Cost of 1 pen = 2 u
Cost of 10 rulers = 10 x 1 u = 10 u
Cost of 7 pens = 7 x 2 u = 14 u
Total cost of 10 rulers and 7 pens
= 10 u + 14 u
= 24 u
4 p = 24 u
1 p = 24 ÷ 4 = 6 u
Amount that Gabby used to buy more pens
= 1 p
= 1 x 6 u
= 6 u
Number of more pens that Gabby bought
= 6 u ÷ 2 u
= 3
Total number of pens that Gabby bought
= 7 + 3
= 10
Answer(s): 10
