Question

the average weight of 5 persons is 61 kg.if each person reduces their weight by 2kg,then their average weight will be 59 kg.is it true?justify
please answer​...

Answer 1

Answer:

New Average = 67 Kg

Step-by-step explanation:

Let

x1 , x2 , x3 , x4 , x5

are weights of five persons

Then

Average of their weights = sum of weights / number of persons

                                          = ( x1 + x2 + x3 + x4 + x5 ) / 5

But according the given condition

Average = 69

So

( x1 + x2 + x3 + x4 + x5 ) / 5 = 69

( x1 + x2 + x3 + x4 + x5 ) = 69 × 5 = 345      

So

( x1 + x2 + x3 + x4 + x5 ) = 345

Now if each loss the weight = 2 Kg

Then Sum of new waits will be given as

( x1 - 2 + x2 - 2 + x3 - 2 + x4 - 2 + x5 - 2 ) = ( x1 + x2 + x3 + x4 + x5 ) - 10

                                                                   = 345 - 10 = 335

And

New average = New sum / 5 = 335 / 5 = 67 Kg

Thus

New Average = 67 Kg

And

59 Kg is not the correct answer.    

Answer 2

Answer:

new average weight will be 59 kg

Step-by-step explanation:

average weight of 5 persons=61 kg

total weight of 5 persons= $61\times 5$=305 kg

since weight reduces by each person is 2 kg, hence the total weight reduces by 5 person =$5\times2$=10 kg

Now,the total weight of 5 person=305-10 kg=295 kg

hence the new average weight=$\frac{total weight}{number of persons}$

                                          =$\frac{295}{5}$

                                           =59 kg