PSLEErika had a collection of stamps from Iran, Thailand and Norway. She had 122 stamps from Iran. 40% of her stamps were from Thailand. She had 42 fewer stamps from Norway than from Thailand.
- What was the total number of stamps in Erika's collection?
- Erika's aunt gave her some stamps from Thailand. Her total collection increased by 20%. What percentage of her collection was from Thailand after that?
(a)
Iran |
Thailand |
Norway |
Total |
122 |
40% |
40% - 42 |
100% |
|
+ 20% |
|
+ 20% |
|
60% |
|
120% |
Total number of stamps
= 40% + 40% - 42 + 122
= 80% + 80
100% = 80% + 80
100% - 80% = 80
20% = 80
1% = 80 ÷ 20 = 4
Total number of stamps in Erika's collection
= 100%
= 100 x 4
= 400
(b)
Old stamp collection = 100%
New stamp collection = 100% + 20% = 120%
Percentage of stamps from Thailand
= 40% + 20%
= 60%
Percentage of her collection from Thailand
=
60120 x 100%
= 50%
Answer(s): (a) 400; (b) 50%