A spends 90% of his salary and B spends 85% of his salary but savings of both are equal find the income of B if sum of their incomes is Rs 5000

Question

A spends 90% of his salary and B spends 85% of his salary but savings of both are equal find the income of B if sum of their incomes is Rs 5000

Answer 1

Since A spends 90% of his salary a, his savings are 0.1a. Since B spends 85% of his salary b, his savings are 0.15b.

 

Since the savings of both are equal, we get our first equation: 0.1a = 0.15b. Since the sum of their incomes is Rs 5000, we get our second equation: a+b = 5000.

 

This is now a simultaneous equation that we can solve for. Multiplying the first equation by 10 and grouping all terms on the left, we get: a–1.5b = 0

 

Subtracting this new equation from a+b = 5000, the a's cancel out and we are left with 2.5b = 5000. Thus b = 2000.