easy question NO2 from disclosure

[magical cook]

Could anyone please give me some example to understand this question?? I am confused..

Which of the following procedures is alwasys equivalent to adding 5 numbers and then deviding the sum by 5?

I. Multiplying the 5 numbers and then finding the 5th root of the product.

II. Adding the 5 numbers, doubling the sum, and then moving the decimal point one place to the left.

III. Ordering the 5 numbers numerically and then selecting the middle number.


A) None
B) I only
C) II only
D) III only
E) I and III


The answer is C

[cooldude]

method 1 - suppose we have numbers 4 8 9 27 1;so fifth root of product is 6

but adding them all then divide by 5 is not equal to 6

method 2-suppose a b c d e are any 5 inteers so sum is a+ b+ c+ d +e
and doubling it is 2(a+ b+ c+ d +e) the divide by 10 is {a+ b+ c+ d +e}/5

method 3-
again take 4 8 9 27 1 so middle no. is 8


hence u c only second is correct

[magical cook]

Thank you so much for your help.

it becomes very clear but one part... (sorry very basic)

as for the method 1
the product of the example 5 numbers: 4 8 9 27 1 will be 7776, and how come 5th root of 7776 is 6??

Thank you...

[cooldude]

break them into factors and make sets of 5 !!!!!!!

there r 5 2s and 5 3s

[magical cook]

Thank you again Cooddue...

I thought 5th root of product is like this (see attached), but actually that means "make 5 sets of factors"

Yes, there are 22222 and 33333.

Thank you!