A can do a piece of work in 20 days and B in 30 days. They work together for 7 days and then both leave the work.  Then C alone finishes the remaining work in 10 days. In how many days will C finish the full work?

In what proportion must a grocer mix sugar at Rs. 12 a kg and Rs. 7 a   kg Sugar as to make a mixture worth Rs 8. a kg?

Alcohol and water in two vessels A and B are in the ratio 5:3 and 5:4 respectively. In what ratio, the liquid of in both the vessels be mixed to obtain a new mixture in vessel C in the ratio 7:5?

In one glass, milk and water are mixed in the ratio 3:5 and in another glass they are mixed in the ratio 6:1.In what ratio should the content of the two glasses be mixed together so that new mixture contains milk and water in the ratio 1:1?

An alloy contains zinc, copper and tin in the ratio 2:3:1 and an other contains copper, tin and lead in the ratio 5:4:3. If equal weights of both alloys are melted together to form a third alloy, then the weight of lead per kg in the new alloy will be.

A tap takes 36 hours extra to fill a tank due to leakage equivalent to half of its inflow. The inflow can fill the tank in how many hours?

12 pumps working 6 hours a day can empty a completely filled reservoir in 15 days. How many such pumps working 9 hours a day will empty the same reservoir in 12 days?

A man standing on the bank of river observes that the angle subtended by a tree on the opposite bank is 60°. When he retrieves 36 m from the bank, he find that the angle is 30°. The breadth of the river is