arun and tarun can do a work in 10 days . after 4 days tarun went to his village . how many days are required to complete the remaining work by arun alone . arun can do the work alone in 30 days .
"they together completed 4 / 10 work in 4 days . balance 6 / 10 work will be completed by arun alone in 30 * 6 / 10 = 18 days . answer : c"
subtract(30, multiply(divide(30, 10), 4))