Question

A man complete a journey in 10 hours. He travels first half of the journey at the rate of 21 km/hr and second half at the rate of 24 km/hr. Find the total journey in km.

• A. 220 km
• B. 224 km
• C. 230 km
• D. 234 km

Answer 1

The correct option is B 224 km

$\frac{\left(1/2\right)x}{21}+\frac{\left(1/2\right)x}{24}=10$
$\Rightarrow \frac{x}{21}+\frac{x}{24}=20$
$\Rightarrow 15x=168\times 20$
$\Rightarrow x=\left(\frac{168\times 20}{15}\right)=224$km.