On Monday, there were 20 more children than adults at the bowling alley. On Tuesday, the number of children increased by 90% and the number of adults increased by 70%. There were 362 people on Tuesday. How many children were there on Monday?
| |
Children |
Adults |
Total |
Comparing children
and adults at first |
20 more |
|
|
| Before |
10 u |
+ 20 |
10 u |
|
| Change |
+ 9 u |
+ 18 |
+ 7 u |
|
| After |
19 u |
+ 38 |
17 u |
362 |
90% =
90100 =
910 90% x 20 =
910 x 20 = 18
20 + 18 = 38
70% =
70100 =
710 Total number of people on Tuesday
= 19 u + 38 + 17 u
= 36 u + 38
36 u + 38 = 362
36 u = 362 - 38
36 u = 324
1 u = 324 ÷ 36 = 9
Number of children on Monday
= 10 u + 20
= 10 x 9 + 20
= 90 + 20
= 110
Answer(s): 110
