While solving a problem, by mistake, Anita squared a number and then subtracted 25 from it rather than first subtracting 25 from the number and then squaring it. But she got the right answer. What was the given number? 

Direction (66-70): What should come in place of the question mark(?) in the following number series?

729, 243, 81, 27, ?

In a box there are 6 blue ball, X red balls & 10 green balls. Probability of choosing one red ball from the given box is $$ {1\over 3}$$. Then find the sum of red and blue balls in the box?

If $$ {cot A={n\over{n+1}}}$$ and $$ {cot B={1\over{2n+1}}}$$ then what is the value of cot (A + B)?

A shopkeeper gains 20 percent by giving a discount of 10 percent of the marked price of a toy. If he had given a discount of 20 percent, then what would be his profit percentage?

A man gives 20% of his money to his eldest son, 30% of remaining he gives to his younger son. 10% of the remaining he gives in a school for poor boys still he has Rs.100.80. Find his total sum. 

The product of two whole numbers is 37. The square root of the difference of the numbers is

A car reaches its destination in time when moving with an average speed of 45 km/hr. But when it is moving at 30 km/hr, it is late by 10 minutes. Find the total distance of the journey?