Question

Average of 11 results is 30.Thatof the first five is 25 and that of the last five is 28 find the value of sixth number

Answer 1

Answer:65

Step-by-step explanation:

Sum of 11 number/(11)=30

Sum of 11 no = 330.

Similarily,

Sum of first 5 no = 25*5=125

Sum of last 5 no = 28*5=140

6th no. = 330-125-140=65=Ans.

Hope u got it!!!

Answer 2

Answer:

65

Step-by-step explanation:

We are given that Average of 11 results is 30.

$Average = \frac{\text{Sum of all observations}}{\text{no. of observations}}$

$30= \frac{\text{Sum of 11 observations}}{11}$

$30 \times 11= \text{Sum of 11 observations}$

$330= \text{Sum of 11 observations}$

Now we are given that Average of first five is 25

So, $25= \frac{\text{First 5 observations}}{5}$

$25 \times 5=\text{First 5 observations}$

$125=\text{First 5 observations}$

Now we are given that Average of last five is 28

So, $28= \frac{\text{Last 5 observations}}{5}$

$28 \times 5=\text{Last 5 observations}$

$140=\text{Last 5 observations}$

So, Sixth number = Sum of 11 observations - (Sum of of first 5 observations + Sum of last 5 observations)

Sixth number = 330 - (125 + 140)

Sixth number = 65

Hence  the value of sixth number is 65