X, Y and Z can do a piece of work in 30, 40 and 50 days respectively. All three of them began the work together but Y left 4 days before completion of the work. In how many days was the work completed?
X can complete 5/7 part of a work in 10 days and Y can complete 3/4 part of the same work in 9 days. In how many days will both complete 13/21 part of the total work?
P can make a table in 16 days while Q can make it in 20 days. Q started the work and did that work for 5 days. In how many days P can complete the remaining work?
Type 1 workers are 2.5 times as efficient as type 2 workers. Twelve Type 1 workers can complete a task in 10 days. How many days would it have taken 4 Type 1 and 15 Type 2 workers to do the same work?