JEE MainMathematicsBinomial Theorem
If the fractional part of the number 3²⁰² 17 is k 17 , where k is an integer such that 0 k < 17 , then the value of k is :
Options
- A9
- B16
- C8
- D1
Correct answer
C. 8
Step-by-step solution
The fractional part of 3²⁰² 17 is given by k 17 , which means k is the remainder when 3²⁰² is divided by 17 . We can write 3²⁰² as 3^2 3²⁰⁰ = 9 (3^4)⁵⁰ . 3²⁰² = 9 (81)⁵⁰ Now, express 81 in terms of a multiple of 17 : 81 = 17 5 - 4 = 85 - 4 Using the binomial theorem, we have: 9 (85 - 4)⁵⁰ = 9 ( 17M + (-4)⁵⁰ ) Thus, the remainder depends on 9 (-4)⁵⁰ . 9 (-4)⁵⁰ = 9 4⁵⁰ = 9 (4^2)²⁵ = 9 (16)²⁵ Now, express 16 as (17 - 1) : 9 (17 - 1)²⁵ = 9 ( 17N + (-1)²⁵ ) 9 (17N - 1) = 17(9N) - 9 The remainder is -9 . Since the remain