A container contains a mixture of acid and water in which water is 24%. If 50% of the mixture is taken out in which water is 156 liters less than the acid, then find the remaining quantity of acid in that container?

Simplify $$ \sqrt{(1-sin^{2}θ) ÷(1-cos^{2}θ)}$$.

Six years ago, the ratio of ages of A to B was 7 : 5. After 4 years from now, the ratio of their ages will be 11 : 9. What is A’s age at present?

Simplify the following

  $${\sqrt { 10+{\sqrt { 25+ {\sqrt { 108 +\sqrt { 154+ \sqrt { 225} \ } \ } \ }} \ } } \ }\over \sqrt { 16+ 19.25×4^2} $$

Price of sugar rises by 20%. By how much percent should the consumption of sugar be reduced so that the expenditure does not change?

A certain sum doubles in 7 years at simple interest. The same sum under the same interest rate will become 4 times in how many years.:

What will come in place of the question mark (?) in each of the following series?

15     ?    24    33     97    122     

1-[5-{2+(-5+6-2)2}] is equal to