Question

what is the average of first 31 multiples of 5​

Answer 1

middle number becomes the average

for 31 middle number is 16

so 5*16=80

and is 80

Answer 2

Answer:

248

Step-by-step explanation:

first 31 multiples of  5

Multiple of 5 are 5,10,15,20,25.... 155

Converting to Arithematic progression

a=5, d=5, n=31

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

= 31/2 (2*5 + (31-1)5)

=31/2(10+(30)5)

=31/2(10+150)

=31/2(160)

=31*8

=248