Question

A student was asked to simplify $\frac{0.6\times 0.6\times 0.6+0.5\times 0.5\times 0.5+0.1\times 0.1-0.09}{0.6\times 0.6+0.5\times 0.5+0.1\times 0.1-0.41}$ and his answer was 0.6 By what per cent was his answer wrong

• A. 25%
• B. 100%
• C. 50%
• D. 120%

Answer 1

Answer: (C)

50%

$\frac{0.6\times 0.6\times 0.6+0.5\times 0.5\times 0.5+0.1\times 0.1-0.09}{0.6\times 0.6+0.5\times 0.5+0.1\times 0.1-0.41}$

$\frac{0.216+0.125+0.01-0.09}{0.36+0.25+0.01-0.41}=\frac{0.261}{0.21}=1.2$

Student got answer as $0.6$

Hence His Answer was wrong with $\frac{0.6}{1.2}\times 100=50$%