bob wants to run a mile in the same time as his sister . if bob ’ s time for a mile is currently 10 minutes 30 seconds and his sister ’ s time is currently 9 minutes 36 seconds , by what percent does bob need to improve his time in order run a mile in the same time as his sister ?
"bob ' s time = 630 secs . his sis ' time = 576 secs . percent increase needed = ( 630 - 576 / 630 ) * 100 = 54 / 640 * 100 = 9 % . ans ( c ) ."
multiply(multiply(10, 10), subtract(const_1, divide(add(multiply(9, const_60), 36), add(multiply(10, const_60), 30))))