• # question_answer Points A and B are 100 km apart on a highway. One car starts from A and another from B at the same time. If the cars travel in the same direction, they meet in 5 hours. If the cars travel towards each other, they meet in 1 hour. What is the speed of the faster car? A)  70 km/hour       B)  40 km/hour C)  60 km/hour       D)  80 km/hour

[c] Let the speed of car be x and other be y Distance covered from A in 5 hrs = 5x Distance covered from B in 5 hrs = 5y ATQ When they travel in same direction Then $5x-\,5y=100$ $x-\,y=20\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,...(i)$                  ? (i) When they travel towards each other Then ATQ \begin{align} & ={{r}_{2}}-\,{{r}_{1}} \\ & {{C}_{2}}-\,{{C}_{1}}=66 \\ & \therefore 2\pi {{r}_{2}}=2\pi {{r}_{1}}=66 \\ & \Rightarrow 2\pi ({{r}_{2}}-\,{{r}_{1}})=66 \\ & \Rightarrow {{r}_{2}}-\,{{r}_{1}}=\frac{66}{2\pi }=\frac{66\times 7}{2\times 22}=10.5\,\,metre \\ \end{align} Now, adding eqn (i), & (ii) $2x=120$         $x=60\,\,km/hr$ 2x=120             x=60 km/hr