Question

find the mean of even no.between 11 to
25​

Answer 1

Step-by-step explanation:

a=12

b=24

Sn=n/2(a+l)

we know that

an=a+(n-1)d

24=12+(n-1)2

24=12+2n-2

24=10+2n

24-10=2n

14=2n

therefore n=7

Sn=7/2(12+24)

=7/2(36)

=7(18)

=126

therefore mean is 126