Question

Callum and Isabel have a total of 240 stamps.
The ratio of the number of Callum's stamps to the number of Isabels's stamps is 3:8
Callum buys some stamps from Isabel.
Please help I will award brainliest. :)
The ratio of the number of Callum's stamps to the number of Isabel's stamps is now 3:2
How many stamps does Callum buy from Isabel?
You must show all your working.

Answer 1

Original ratio: 3 + 8 = 11

240/11 = 21.818

3 x 21.818 = 65.5

11 x 21.818 = 174.5

New ratio: 3 + 2 = 5

240/5 = 48

3 x 48 = 144

2 x 48 = 96

Number of stamps bought = new amount - original amount:

144-65.5 = 78.5

Round to nearest whole number = 79 stamps bought