a can run 4 times as fast as b and gives b a start of 63 m . how long should the race course be so that a and b might reach in the same time ?
"speed of a : speed of b = 4 : 1 means in a race of 4 m a gains 3 m . then in a race of 63 m he gains 63 * ( 4 / 3 ) i . e 84 m answer : e"
add(multiply(4, divide(divide(63, 4), subtract(4, const_1))), 63)