If a=x+y, b=x-y, c=x+2y, then $$ {a^2+b^2+c^2}-ab-bc-ca $$ is

Alex sold his goods after announcing two successive discounts of 30% each. The effective discount altogether is-

How many kilogram of rice costing Rs.60 per kg must be mixed with 24 kg of rice costing Rs.42 per kg so that there may be a gain of 12% by selling the mixture at Rs.56 per kg?

The price of one eraser is Rs. 3. The value of 20 eraser is equal to the value of three Pens. The value of one pen is equal to the value of two pencils and the value of six pencils is equal to the value of five markers. What is the value of one marker?

A vessel contains 60 litres of milk. 12 litres of milk taken out from it and replaced with water. Then again form mixture, 12 litres is taken out and replaced with water. The ratio of milk and water in the resultant mixture is :

There are two inlets A and B connected to a tank. A and B can fill the tank in 32 h and 28 h, respectively. If both the pipes are opened alternately for 1 h, starting with A, then in how much time (in hours, to nearest integer) will the tank be filled? 

Find the least multiple of 23, which when divided by 18, 21 and 24 leaves the remainder 7, 10 and 13 respectively.

if θ is acute angle and sin (θ+18⁰) = 1/2, then the value of θ in circular measure is :