Question

2+4+6+8+................+n = 240 What is the value of n ?
(Created by Ímdad Uddin Mazumder)
A.15
B.16
C.20
D.17​

Answer 1

Answer:

Step-by-step explanation:

240= n/2 (2a + (n-1)d)

where a=2

d=2

n² + n - 240

n = 30 ; n = -32

negative value rejected