SarkariPYQ

SSC CGL 2021 PYQ — Question 68

SSC CGL - 20 Aug 2021 - Shift 1 • Quantitative Aptitude • Q68

Back to paper

A takes 2 hours more than B to cover a distance of 40 km. If A doubles his speed, he takes 112\frac{1}{2} hour more than B to cover 80 km. To cover a distance of 120 km, how much time (in hours) will B take, travelling at the same speed?

Show answer & explanation

Correct answer: D

Explanation

The correct answer is option 4 i.e.  112\frac{1}{2}

Let the speed of A and B be 'a' km/hr and 'b' km/hr.

40/a - 40/b = 2 .............(1)

80/2a - 80/b = 3/2 .......(2)

On subtracting eq(2) from (1) we get,

-40/b + 80/b = 1/2

b = 80 km/hr.

Time taken by B to cover 120km = 120/80 =  112\frac{1}{2} hours.