A box contained grey and silver pens. There were 60% more grey pens than silver pens. When 22 more pens were poured into the box, the amount of grey pens increased by 25% and the amount of silver pens increased 70%. How many pens were in the box at first?
| |
Grey pens |
Silver pens |
Total pens |
| Before |
8 u |
5 u |
13 u |
| Change |
+ 2 u |
+ 3.5 u |
+ 5.5 u |
| After |
10 u |
8.5 u |
18.5 u |
100% + 60% = 160%
160% =
160100 =
85Number of more grey pens that were poured into the box
= 25% x 8 u
=
25100 x 8 u
= 2 u
Number of more silver pens that were poured into the box
= 70% x 5 u
=
70100 x 5 u
= 3.5 u
Total number of more pens that were poured into the box
= 2 u + 3.5 u
= 5.5 u
5.5 u = 22
1 u = 22 ÷ 5.5 = 4
Number of pens in the box at first
= 8 u + 5 u
= 13 u
= 13 x 4
= 52
Answer(s): 52
