Question

The sum of cubes of first few even numbers is 1800. What is the sum of these numbers ?

• A. 20
• B. 25
• C. 30
• D. 35

Answer 1

Answer:

C. 30

Sum of cubes of first n even numbers = 2(n(n+1))² 2(n(n+1)²=1800 (n(n+1))²=1800/2 (n(n+1))²=900 n(n+1)=√900=30