A shopkeeper increases the price of an object by 40 % and then sells it at 25 % discount on the marked price. If the selling price of such an object be ₹ 2100, its cost price for the shopkeeper was? 

What is the average of the following numbers?
38, 92, 45, 25, 60

A boat is moving away from an observation tower. It makes an angle of depression of 60 ° with an observer's eye when at a distance of 50 m from the tower. After 8 sec, the angle of depression becomes 30 °. By assuming that it is running in still water, the approximate speed of the boat is 

The numbers 1, 3, 5, 7______99 and 128 are multiplied together. The number of zeros at the end of the product must be: 

If a : b = 7 : 9 and b : c = 5 : 7, then what is a : c ?

How many three-digit numbers are there in which all the digits are odd? 

If a+b+c=15 and a²+b²+c²=83 then the value of a³+b³+c³-3abc

A bus can travel $$ 12{2\over5}$$ Km in one hour. How much distance will it cover in $$ 2{3\over4}$$ hours?