Direction : What should come in place of the question (?) in the following question.

(?)² + (65)²=(160)² -  (90)² – 7191

An article is sold at a loss of 40%. The nominal amount of loss is approximately what percentage of the selling price of the article?

If a sum of money becomes 8 times in 9 years at compound interest annually, in how much time it will become 32 times?

A tank is 25m long 12m wide and 6m deep. The cost of plastering its walls and bottom at 225 paise per sq m is

The value of  $${cosec^2} 18° -{1\over cot^272°}$$.

A certain sum becomes Rs. 1020 in 5 years and Rs. 1200 in 8 years at simple interest. What is the value of principal? 

A basket consists of five blue balls, four green balls, two red balls and three yellow balls. Three balls are drawn at random. What is the probability that at least one blue ball is drawn?

A scientist mixes 10% water in his solution but he is not content with it so he again mixes 10% more water in the previous mixture. What is the profit percentage of the scientist if he sells it at cost price: