On Friday, there were 10 more children than adults at the trampoline park. On Saturday, the number of children increased by 90% and the number of adults decreased by 70%. There were 85 people on Saturday. How many adults were there on Friday?
| |
Children |
Adults |
Total |
Comparing children
and adults at first |
10 more |
|
|
| Before |
10 u |
+ 10 |
10 u |
|
| Change |
+ 9 u |
+ 9 |
- 7 u |
|
| After |
19 u |
+ 19 |
3 u |
85 |
90% =
90100 =
910 90% x 10 =
910 x 10 = 9
10 + 9 = 19
70% =
70100 =
710 Total number of people on Saturday
= 19 u + 19 + 3 u
= 22 u + 19
22 u + 19 = 85
22 u = 85 - 19
22 u = 66
1 u = 66 ÷ 22 = 3
Number of adults on Friday
= 10 u
= 10 x 3
= 30
Answer(s): 30
