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 :
"to reach the winning post a will have to cover a distance of ( 500 - 140 ) m , i . e . , 360 m . while a covers 3 m , b covers 4 m . while a covers 360 m , b covers 4 x 360 m = 480 m . 3 thus , when a reaches the winning post , b covers 480 m and therefore remains 20 m behind . a wins by 20 m . answer : d"
subtract(500, divide(multiply(subtract(500, 140), 4), 3))