KVPY2015MathematicsBasics of Mathematics
If n is the smallest natural number such that n+2 n+3 n+ .+99 n is a perfect square, then the number of digits in n² is
Options
- A1
- B2
- C3
- Dmore than 3
Correct answer
C. 3
Step-by-step solution
array l n +2 n +3 n + .+99 n n (1+2+3+ +99) array n (99)(100) 2 =9 25 22 n is a perfect square when n =22 Number of digits in n =3