On Friday, there were 10 more adults than children at the arcade. On Saturday, the number of adults increased by 70% and the number of children increased by 90%. There were 305 people on Saturday. How many adults were there on Friday?
| |
Adults |
Children |
Total |
Comparing adults
and children at first |
10 more |
|
|
| Before |
10 u |
+ 10 |
10 u |
|
| Change |
+ 7 u |
+ 7 |
+ 9 u |
|
| After |
17 u |
+ 17 |
19 u |
305 |
70% =
70100 =
710 70% x 10 =
710 x 10 = 7
10 + 7 = 17
90% =
90100 =
910 Total number of people on Saturday
= 17 u + 17 + 19 u
= 36 u + 17
36 u + 17 = 305
36 u = 305 - 17
36 u = 288
1 u = 288 ÷ 36 = 8
Number of adults on Friday
= 10 u + 10
= 10 x 8 + 10
= 80 + 10
= 90
Answer(s): 90
