Question

(SSC CPO 20-03-2016, Evening) 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 और B बिन्दु राजमार्ग पर 100 किमी. दूरी

SSC CGL

Maths

Solution

4.0 (1 ratings)

Car A is faster car A is at point A Car B is at point B Let them move in same direction ond meet at ( C ); time taken ( =5 ) hrs Relotive velocity of cars ( =V_{A}-V_{B} ) moving in some Total distance covered ( =(100+x) mathrm{km} ) [ therefore quad v_{A}-v_{B}=frac{100+x}{5} ] ( cos B ) took 5 hrs to Cover distance ( x ) [ therefore-V_{B}=frac{x}{5}, quad therefore quad x=5 vee_{B} longrightarrow ] Putting eq ( sqrt{2} quad ) in [ begin{aligned} V_{A}-V_{B}=frac{100+5 V_{B}}{5} &=5 v_{A}-5 v_{B}=100+5 mathrm{s}_{B} Rightarrow & v_{A}-2 V_{B}=20 rightarrow(3) end{aligned} ] Opbosite direction let the cors ( V_{A}+V_{B}=frac{100}{1} rightarrow Q[text { is Time toleen is } mid h r] ) Eguoting (3) (4) Multiplying eq 4 ) ( V A-2 V B=20 rightarrow ) (3) With ( 2^{2}(V A+V B=100) rightarrow 4 ) 73.7