a 90 cm long wire is to be cut into two pieces so that one piece will be 2 / 5 th of the other , how many centimeters will the shorter piece be ?
"1 : 2 / 5 = 5 : 2 2 / 7 * 90 = 25 answer : a"
subtract(90, divide(90, add(divide(2, 5), const_1)))