Ahmad, Simon and Bala share a sum of money in the ratio 3 : 2 : 5.
If Bala has $900 more than Simon, what is the sum of money being shared by the three of them? Answer $ ___

1. Relate the given difference in money to the difference in ratio parts.

Bala : Simon $= 5 : 2$

Difference in ratio parts $= 5 - 2 = 3$ parts

So, $3$ parts $= \char36{}900$.

2. Find the total amount shared by all three people.

$1$ part $= \char36{}900 \div 3 = \char36{}300$

Total ratio parts $= 3 + 2 + 5 = 10$

Total amount $= 10 \times \char36{}300 = \char36{}4500$