bob wants to run a mile in the same time as his sister . if bob ’ s time for a mile is currently 10 minutes 40 seconds and his sister ’ s time is currently 5 minutes 20 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 = 640 secs . his sis ' time = 320 secs . percent increase needed = ( 640 - 320 / 640 ) * 100 = 320 / 640 * 100 = 50 % . ans ( b ) ."
multiply(multiply(10, 10), subtract(const_1, divide(add(multiply(5, const_60), 20), add(multiply(10, const_60), 40))))