6 क्रमागत सम संख्याओ का औसत 25 हो तो सबसे बड़ी तथा सबसे छोटी संख्या का अंतर ज्ञात करे?

Options

A. 8
B. 10
C. 15
D. 18

Answer

B

Explanation

According to question
Sum of 6 consecutive even number is =25 x 6 =150
`Sn=n/2(2a+(n-1)d)`
`150=6/2(2a+(6-1)xx2)`
`150=6/2(2a+10)`
300=12a+60
12a=240
`a=240/12=20`
`therefore` Numbers are 20,22,24,26,28,30
=30-20=10
Alternate
Let the 6 consecutive no is = x, x+2, x+4, x+6, x+8, x+10
A.T.Q.
largest number =avg. + (n-1) = 25+5=30
smallest number = avg. - (n-1)=25-5 =20
Diff. between largest and smallest no 30-20 =10