in a 100 m race , a covers the distance in 36 seconds and b in 45 second . in this race a beats b by :
"solution distance covered by b in 9 sec . = ( 100 / 45 x 9 ) m = 20 m . ∴ a beats b by 20 metres . answer a"
multiply(divide(100, 45), subtract(45, 36))