The number of pairs of natural numbers the difference of whose squares is 45 will be –

What value will come in place of question mark (?) in the questions given below?
6⁹ × 36 ÷ 7776 = 6^? ÷ 216 

Two numbers are respectively 30% and 40% less than a third number. What percent is the first number of the second?

What will be remainder if (13)³ is subtracted from (66)² ?

What is the sum of first 14 natural numbers?

The difference between the greatest and least five-digit numbers formed by the digits 2,5,0,6,8 is (repetition of digits are not allowed) 

The sum of two digit number is 16. If the digit is interchanged the number is formed 18 less than the original number. Find the original number.

If the sum of first three natural numbers from a group of six consecutive natural numbers is 36, then the sum of last three natural numbers will be?