Explanation:
Assuming that the total stamp is x
According to the question
Izzati's stamps is 1/4
Ailing's number of stamps is 1/8
X= 1/4 x 1/8 = 5/8 - the remaining stamps.
Rina’s number of stamps is 7/10 x 5/8 = 35/80 x
5/8 x 35/80 = 15/80 - (Susan's stamps)
According to the question
15/80 = 42
X: 224
the total number of stamps originally is 224.