Direction : What value should come in the place of question mark (?) in the following questions?

$$ 68\sqrt?-826=262 $$

Direction : What value should come in place question mark(?) in the following questions?

0.75 % of 90 + 0.55 % of 80=?

A number is divided by 6 and 5 is added to this quotient Again sum is divided by 9 and the quotient obtained is 1. Find the number.

If a 7-digit number 54p3987 is divisible by 11 , then p is equal to:

A number consists of two digits and the digit in the ten's place exceeds that in the unit's place by 5. If 5 times the sum of the digits be subtracted from the number, the digits of the number are reversed. Then the sum of the digits of the number is:

Directions: Find the wrong number in the following number series:

0.5, 2, 1, 4, 32, 512, 16384

A number is doubled and 9 is added. If the resultant is tripled, it becomes 75. What is that number? 

The number will be, whose square is equal to the difference between the squares of 975 and 585, is: