There was an equal number of benches and stools in the morning. At 1 p.m., some benches were added and some stools were removed, resulting in the number of benches being increased by 20% while the number of stools decreased by 20%. At 6 p.m. the number of benches increased by 50%. If a total of 60 benches were added during the day, how many more benches than stools were there in the end?
At 1 p.m. |
Benches |
Stools |
Before |
1 u |
1 u |
Change |
+ 0.2 u |
- 0.2 u |
After |
1.2 u |
0.8 u |
At 6 p.m. |
Benches |
Stools |
Before |
1.2 u |
0.8 u |
Change |
+ 0.6 u |
No change |
After |
1.8 u |
0.8 u |
Number of benches added
= 20% x 1 u
=
20100 x 1 u
= 0.2 u
Number of stools removed
= 20% x 1 u
=
20100 x 1 u
= 0.2 u
Number of benches increased by benches at 6 p.m.
= 50% x 1.2 u
=
50100 x 1.2 u
= 0.6 u
Number of benches added during the day
= 1.8 u - 1 u
= 0.8 u
0.8 u = 60
1 u = 60 ÷ 0.8 = 75
Number of more benches than stools in the end
= 1.8 u - 0.8 u
= 1 u
= 1 x 75
= 75
Answer(s): 75