Practicing Success

Target Exam

CUET

Subject

General Test

Chapter

Numerical Ability

Topic

Time, Speed and Distance

Question:

A and B started their journeys from X to Y and Y to X, respectively.  After crossing each other, A and B completed their remaining journey in 6\(\frac{1}{8}\) and 8 h respectively.  If speed of A is 32 km/h, find the speed of B (km/h).

Options:

28

21

25

34

Correct Answer:

28

Explanation:

Let meeting time = t hours,

speed of A = S1 and speed of B = S2

time taken by A after meeting = t1

time taken by B after meeting = t2,

ATQ,

t= 6\(\frac{1}{8}\) = \(\frac{49}{8}\)

t= 8

\(\frac{S_1}{S_2}\) = \(\sqrt {\frac{t_2}{t_1}}\)

\(\frac{32}{S_2}\) = \(\sqrt {\frac{\frac{49}{8}}{8}}\)

\(\frac{32}{S_2}\) = \(\sqrt {\frac{64}{49}}\)

\(\frac{32}{S_2}\) = \(\frac{8}{7}\)

S2  = 7 × 4 = 28