The mean of `a ,\ b ,\ c ,\ d\ a n d\ e\ i s\ 28.` If the mean of `a ,\ c ,\ a n d\ e\ i s\ 24` , what is the mean of `b\ a n d\ d ?` 31 (b) 32 (c) 33 (d) 34

Explanation

Given : Mean of 5 numbers a,b,c,d,e is `28`
`therefore (a+b+c+d+e)/5=28`
`(a+c+e)/5+(b+d)/5=28`
It is also given that Mean of 3 numbers a,c,e is `24`
`therefore (a+c+e)/3=24`
`therefore a+c+e=72`
`(a+c+e)/5+(b+d)/5=28`
`72/5+(b+d)/5=28`.......Substituting the value of a+c+e
`(b+d)/5=28-72/5`
`(b+d)/5=28-14.4`
`(b+d)/5=13.6`
`b+d=68`
Mean of `(b+d)/2=68/2`
`(b+d)/2=34`
`therefore` Mean of `b+d=34`