App Logo

No.1 PSC Learning App

1M+ Downloads
Find the sum first 20 consecutive natural numbers.

A200

B210

C220

D205

Answer:

B. 210

Read Explanation:

sum first n consecutive natural numbers =n(n+1)/2 sum first 20 consecutive natural numbers = 20(21)/2 = 10 × 21 = 210


Related Questions:

How many three digit numbers which are divisible by 5?
തുടർച്ചയായ 5 സംഖ്യകളുടെ തുക 35 ആയാൽ അവസാനത്തെ സംഖ്യ ഏതാണ്?
0.4, 1.1, 1.8, ... are the first three terms of an arithmetic sequence. The first natural number of the sequence is:
Find 3+6+9+ ... + 180.
Find the 17th term of an arithmetic progression. If 15th and 21st term of arithmetic progression is 30.5 and 39.5 respectively.