A trader had 16 quintals of wheat. He sold a part of it at 17% profit and the rest at 27% profit, so that he made a total profit of 21%. How much wheat did he sell at 27 % profit? 

Three numbers which are co-prime to one another are such that the product of the first two is 551 and that of the last two is 1073. The sum of the three numbers is: 

(0.04)^-1.5 on simplification gives: 

N is the smallest three digit prime number. When N is divided by 13, then what will be the remainder? 

A watch which gains uniformly is 4 minutes slow at 9 A.M on Sunday and is 4-minute 15 sec. fast at 9 P.M on the upcoming Friday. When was it correct? 

Two trains of equal length take 10 seconds and 15 seconds respectively to cross a telegraph post. If the length of each train be 120 meters, in what time (in seconds) will they cross each other traveling in opposite direction? 

In an alloy, the ratio of copper and zinc is 5 : 2. If 1.250 kg of zinc is mixed in 17 kg 500 g of alloy, then the ratio of copper and zinc will be 

The students in three classes are in the ratio 2 : 3 : 5. If 20 students are increased in each class, the ratio changes to 4 : 5 : 7 . originally the total number of students was: