PSLEAnna had a collection of stamps from Korea, Russia and Finland. She had 180 stamps from Korea. 40% of her stamps were from Russia. She had 20 fewer stamps from Finland than from Russia.
- What was the total number of stamps in Anna's collection?
- Anna's aunt gave her some stamps from Russia. Her total collection increased by 20%. What percentage of her collection was from Russia after that?
(a)
Korea |
Russia |
Finland |
Total |
180 |
40% |
40% - 20 |
100% |
|
+ 20% |
|
+ 20% |
|
60% |
|
120% |
Total number of stamps
= 40% + 40% - 20 + 180
= 80% + 160
100% = 80% + 160
100% - 80% = 160
20% = 160
1% = 160 ÷ 20 = 8
Total number of stamps in Anna's collection
= 100%
= 100 x 8
= 800
(b)
Old stamp collection = 100%
New stamp collection = 100% + 20% = 120%
Percentage of stamps from Russia
= 40% + 20%
= 60%
Percentage of her collection from Russia
=
60120 x 100%
= 50%
Answer(s): (a) 800; (b) 50%