'X' alone can do a work in 48 days and the efficiency of 'X' is 33.33% more than that of 'Y'. They together start working and worked for 6 days and after that, another person 'Z' joins them and together they finish the remaining work in 10 more days. If the share of 'Y' is 1312.5 Rs. then find the total amount for which they undertook to do the given work.