What is the greatest integer among the following by which the number 55 + 75 is divisible?

What is the greatest integer among the following by which the number 55 + 75 is divisible? Correct Answer 12

Concept:

Formula used:

  • an + bn = {a + b} × {an-1 - an-2b + an-1b2 – ⋯ – abn-2 + bn-1}


Calculation:

Using an + bn = {a + b} × {an-1 - an-2b + an-1b2 – ⋯ – abn-2 + bn-1}

55 + 75 = {5 + 7} × {54 – 53 × 7 + ⋯ +74}

= 12 × {54 – 53 × 7 + ⋯ +74}

Hence, 55 + 75 is divisible 12.

Related Questions

If (x)2 = [x]2 + 2x then which of the following is true. Where [x] represents greatest integer less than or equal to x. (x) represents integer just greater than or equal to x. I represents Integer.