Discussion :: Numbers
-
The sum of even numbers between 1 and 31 is:
Whatsapp
Facebook
Answer : Option C
Explanation :
Let Sn = (2 + 4 + 6 + ... + 30). This is an A.P. in which a = 2, d = 2 and l = 30
Let the number of terms be n. Then,
a + (n - 1)d = 30
2 + (n - 1) x 2 = 30
n = 15.
Sn =\(\frac { n} { 2 }(a+1) \)=\(\frac { 15 } { 2 } \) x (2 + 30) = (15 x 16) = 240.
Be The First To Comment