a runs twice as fast as b and gives b a start of 42 m . how long should the racecourse be so that a and b might reach in the same time ?
"ratio of speeds of a and b is 2 : 1 b is 42 m away from a but we know that a covers 1 meter ( 2 - 1 ) more in every second than b the time taken for a to cover 42 m is 42 / 1 = 42 m so the total time taken by a and b to reach = 2 * 42 = 84 m answer : c"
multiply(42, const_2)