Ivory had 21 more stamps than Anna. After Anna gave away
13 of her stamps, Ivory had five times as many stamps as Anna. How many stamps did Anna have at first?
| |
Ivory |
Anna |
Comparing Ivory and
Anna at first |
21 more |
|
| Before |
10 u |
3 u |
| Change |
|
- 1 u |
| After |
10 u |
2 u |
Comparing Ivory and
Anna in the end |
5x2 =
10 u |
1x2 =
2 u |
Number of stamps that Anna had in the end is repeated. Make the number of stamps that Anna had in the end the same. LCM of 1 and 2 is 2.
Number of stamps that Ivory had at first = 10 u
Number of stamps that Ivory had more than Anna at first
= 10 u - 3 u
= 7 u
7 u = 21
1 u = 21 ÷ 7 = 3
Number of stamps that Anna had at first
= 3 u
= 3 x 3
= 9
Answer(s): 9
