in a 80 meters race a beats b by 56 m or 7 seconds . a ' s time over the course is :
"b runs 56 m in 7 sec . = > b runs 80 m in 7 / 56 * 80 = 10 seconds since a beats b by 7 seconds , a runs 80 m in ( 10 - 7 ) = 3 seconds hence , a ' s time over the course = 3 seconds answer : a"
subtract(multiply(divide(7, 56), 80), 7)