In the given figure ΔDEF is right angle triangle, ∠G=120° and DG=12 cm , GF=10 cm then find out the value of DF.

In the following figure if OA=10 and AC=16, then OB must be:

What should come in place of the question mark (?) in the following question?
19.5% of 524 = 50% of ?

The cost price of an article is Rs x. It is marked up by 200%. It is sold at Rs. 540 after giving 25% discount. What is the value of x (in Rs)? 

The height of a light house is 20 meters above sea level. The angle of depression (from the top of the lighthouse) of a ship in the sea is 30°. What is the distance of the ship from the foot of the light house?

In a village, each of the 60 % of families has a cow; each of the 30 % of families has a buffalo and each of the 15 % of families has both a cow and a buffalo. in all there are 96 families in the village. How many families do not have a cow or a buffalo? 

Average of 11 number is 30. If the average of first 10 numbers is 22, then find the 11th number?