x can do a piece of work in 20 days . he works at it for 10 days and then y finished it in 12 days . how long will y take to complete the work ?
"work done by x in 10 days = 10 * 1 / 20 = 1 / 2 remaining work = 1 - 1 / 2 = 1 / 2 1 / 2 work is done by y in 12 days whole work will be done by y in 12 * 2 = 24 days answer is c"
multiply(12, inverse(subtract(const_1, divide(10, 20))))