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MCQs Math


Question:     If the average of five consecutive even numbers is 16, then find the smallest and the greatest numbers.


Correct Answer  12 and 20

Solution And Explanation

Solution

Some Important Terms Used in the given Question

Consecutive Numbers: Numbers in the continuation are called Consecutive Numbers, for example, 1, 2, 3, 4, . . . etc.

Even Number:
Numbers that can be divided exactly by 2, i.e. leaving no remainder after dividing by 2, are known as Even Numbers

Consecutive Even Numbers:
Even numbers in the continuation are called Consecutive Even Numbers, such as 2, 4, 6, 8, . . . . etc.

How to get next consecutive even numbers to the given even number

Here, it can be observed easily, that there is a difference of 2 between two consecutive even numbers. This means the next consecutive even number can be obtained by the addition of 2 in an even number.

Example:

If 2 is the first even number, then second consecutive even number to 2

= 2 + 2 = 4

Similarly, the third consecutive even number to 2

= 2 + 2 + 2 = 2 + 4 = 6

And, the fourth consecutive even number to 2

= 2 + 2 + 2 + 2 = 2 + 6 = 8 and so on.

In short, next consecutive even number can be obtained by adding 2 in an even number.

Now, Solution of the given Question

Let first even number = x.

Therefore, the second consecutive even number = x + 2

And, the third consecutive even number = x + 4

And, the fourth consecutive even number = x + 6

And, the fifth consecutive even number = x + 8

Now,

the formula to find the

Average = Sum of observations/Numbers of observations

Therefore, the average of the given five consecutive even numbers

= Sum of the five consecutive even numbers/5

⇒ 16 = x+(x+2)+(x+4)+(x+6)+(x+8)/5

⇒ 16 = x+x+2+x+4+x+6+x+8/5

⇒ 16 = 5x + 20/5

After taking 5 as common from the numerator

⇒ 16 = 5 (x + 4)/ 5

⇒ 16 = x + 4

⇒ x + 4 = 16

After transposing 4 to RHS

⇒ x = 16 – 4

⇒ x = 12

Thus, first and the smallest even number = 12

And, the 5th and the greatest even number = x + 8

= 12 + 8 = 20

∴ The 5th and the greatest even number = 20

Therefore, the smallest and the greatest even numbers among the given consecutive five even numbers = 12 and 20 Answer


Similar Questions

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(2) Find the average of even numbers from 6 to 986

(3) What will be the average of the first 4611 odd numbers?

(4) Find the average of the first 2226 odd numbers.

(5) Find the average of the first 2304 even numbers.

(6) Find the average of odd numbers from 3 to 187

(7) What will be the average of the first 4599 odd numbers?

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(9) Find the average of odd numbers from 13 to 225

(10) Find the average of the first 2461 even numbers.


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