Question

Find the value of 1-6+2-7+3-8.......upto 120 terms

Answer 1

Answer:

term 1 = 1-6

          = -5

term 2 = 2-7

           = -5

term 3 = 3-8

           = -5

total number of terms = 120

sum of n terms = n/2(2a + (n-1)d)

sum of 120 terms = 120 * (-5)

                          = -600

Step-by-step explanation: