On Thursday, there were 30 more adults than children at the laser tag park. On Friday, the number of adults increased by 70% and the number of children increased by 90%. There were 339 people on Friday. How many adults were there on Thursday?
| |
Adults |
Children |
Total |
Comparing adults
and children at first |
30 more |
|
|
| Before |
10 u |
+ 30 |
10 u |
|
| Change |
+ 7 u |
+ 21 |
+ 9 u |
|
| After |
17 u |
+ 51 |
19 u |
339 |
70% =
70100 =
710 70% x 30 =
710 x 30 = 21
30 + 21 = 51
90% =
90100 =
910 Total number of people on Friday
= 17 u + 51 + 19 u
= 36 u + 51
36 u + 51 = 339
36 u = 339 - 51
36 u = 288
1 u = 288 ÷ 36 = 8
Number of adults on Thursday
= 10 u + 30
= 10 x 8 + 30
= 80 + 30
= 110
Answer(s): 110
