Question

Akira and Hideo are twins with different jobs. Akira earns five-eighths of what Hideo earns, but Akira's expenses are half of Hideo's. Akira ends up saving 40% of his income. What percentage of his income does Hideo save?

Answer 1

25%

Explanation:

Let x represent Akira income and let y represent Hideo income.

Since Akira earns five-eighths of what Hideo earns, therefore Akira income is given by:

x = (5/8)y

Let a represent Akira expenses and let y represent Hideo expenses. Since Akira expenses is half of Hideo, hence:

a = (1/2)b; b = 2a

Given that Akira savings is 40% of his income, we have:

savings = income - expenses

40% of x = x - a

a = x - 0.4x

a = 0.6x

For Hideo:

Income = y, expenses = b = 2a

Savings = income - expenses

Savings = y - 2a

Savings = y - 2(0.6x) = y - 1.2x

Savings = y - 1.2(5/8)y

saving = y - 6y/8

savings = 2y/8 = 0.25y

Therefore Hideo saves 25% of his income