The average of the first three numbers is double of the fourth number. If the average of all the numbers is 12. Find the 4th number

The average of the first three numbers is double of the fourth number. If the average of all the numbers is 12. Find the 4th number.

The average of the first three numbers is double of the fourth number. If the average of all the numbers is 12. Find the 4th number.

Answer :

Let the fourth number be x

Then , average of first three = 2x

So, the sum of three numbers = 3*2x = 6x

Since, the average of four numbers = 12

Sum of four numbers = 4*12 = 48

x + 6x = 48

7x = 48

x = 48/7

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03rd January 2019

vitorr maths

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