In a 500 m race, the ratio of the speeds of two contestants A and B is 3:4. A has a start of 140 m. Then, A wins by:

Correct option is C

 Given speed ratio of A and B = 3:4

A has a 140 m start, so A runs 360 m while B runs 500 m.

Since speed is in the ratio 3:4, time taken by both is the same:

Solving for x (distance by which A wins):

                              360 x 4 / 3  =  500 - 

                                     1440 / 3 = 500 - 

                              480 = 500 - 

                               = 500 - 480

                              = 20 meters