NextMockSearch exams, e.g. SSC CGL, UPPSC, Lekhpal
Railways PYQCBT 1 2020

RRB NTPC · Question 46

If 1^2 + 2^2 + 3^2 + ....... + 14^2 = 1015, then 3^2 + 6^2 + 9^2 + ...... + 42^2 is equal to

  1. 9135

  2. 9325

  3. 9315

  4. 9235

Show answer & explanation

Answer: (A) 9135

Explanation

3² + 6² + … + 42² = 3²(1² + 2² + … + 14²) = 9 × 1015 = 9135.