Question

find the mean 1st 50 even number

Answer 1

First even number = 2

50th even number = 100

sum of 50 even number = 2 + 100 / 2 × 50

= 102 /2 × 50

= 51 × 50

= 2550

Mean = 2550/50

= 51

Answer 2

Hi ,

2 , 4 , 6 , ....., 100 are first 50 even

numbers .

These are in Arithmetic progression.

First term = a = 2

common difference ( d ) = a2 - a1

d = 4 - 2 = 2

Number of terms = n = 50

nth term = an = 100

Sum of n terms = Sn = n/2 [ a + an ]

S50 = 50/2 [ 2 + 100 ]

= 25 × 102

= 2550 ---( 1 )

Mean = Sn / n

= 2550/50

= 51

I hope this helps you.

: )