On Saturday, there were 30 more adults than children at the night market. On Sunday, the number of adults decreased by 90% and the number of children decreased by 70%. There were 31 people on Sunday. How many adults were there on Sunday?
| |
Adults |
Children |
Total |
Comparing adults
and children at first |
30 more |
|
|
| Before |
10 u |
+ 30 |
10 u |
|
| Change |
- 9 u |
- 27 |
- 7 u |
|
| After |
1 u |
+ 3 |
3 u |
31 |
90% =
90100 =
910 90% x 30 =
910 x 30 = 27
30 - 27 = 3
70% =
70100 =
710 Total number of people on Sunday
= 1 u + 3 + 3 u
= 4 u + 3
4 u + 3 = 31
4 u = 31 - 3
4 u = 28
1 u = 28 ÷ 4 = 7
Number of adults on Sunday
= 1 u + 3
= 1 x 7 + 3
= 7 + 3
= 10
Answer(s): 10
