Question

There are four numbers. Average of the first three is 20 and that of last three is 19. if the last number is 22 find the first number?

Answer 1

Answer:

25

Step-by-step explanation:let the numbersame be a,b, c, d

Now given that

a+b+c÷3=20

then sum of abc is 60

On continuing the process we get a=25

Answer 2

Answer:

First number will be 25.

Step-by-step explanation:

Let four numbers are a, b, c, d

Given last number is 22

So d = 22

Now according to question average of the first three numbers is 20

(a + b + c)/3=20

a + b + c = 60..........(i)

And given that average of the last three numbers is 19.

(b + c + d)/3 = 19

b + c + d = 57

∵ d = 22

b + c + 22 = 57

b + c = 35.........(ii)

After putting value of (b + c) from equation (ii) to equation (i)

a + 35 = 60

a = 25

So first number will be 25.

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