Question

The ratio of Zaidi's savings to Khairi's savings is 7:2. The two of them save $3600. How much is Khairi's savings?

Answer 1

total 7+ 2 = 9
Zaidi's savings = 7/9's of $3600
Khairi's savings = 2/9's of $3600

[ Note the word 'of' is often used in maths to imply 'multipication' i.e. 1/3 of 200]  
Zaidi's savings = 7/9 x $3600= $2800
Khairi's savings = 2/9 x $3600 = $800 
You can check your answer by adding the two amounts together: $2800 + $800 = $3600.