AP EAMCET202422 May 2024Evening ShiftMathematicsBinomial TheoremActual
If P is the greatest divisor of 49^ n +16 n-1 for all n ~N , then the number of factors of P is
Options
- A12
- B15
- C7
- D13
Correct answer
C. 7
Step-by-step solution
aligned & 49^n+16 n-1=(1+48)^n+16 n-1 = & 1+ ^n C₁(48)+ ^n C₂(48)^2+ .+ ^n C_n(48)^n+16 n-1 = & (48 n+16 n)+ ^n C₂(48)^2+ .+ ^n C_n(48)^n = & 64 n+8^n ( ^n C₂ 6^2+ ^n C₃ 6^3 8+ + ^n C_n 6^n 8^ n-2 ) aligned Hence, 49^ n +16 n-1 is divisible by 64 and factors of 64 are 1,2,4,8,16,32,64 . So, number of factors =7