Question

I need help!!!!!!!!!!! PLEASE EXPLAIN! I'M SO CONFUSED! PLEASE! ​

Answer 1

There are 2 14 year olds. The answer is (A).
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The average should be 12. 11 is one less than 12. You have four 11 year olds. You get a deficit of 1 with each 11 year old, so with four of them the deficit is 4. To compensate for this and being the average to 12, you need to make a surplus of 4. If you add one 14 year old, you make a surplus of 2 (because 14 is 2 more than 12). If you add another 14 year old, you now have a surplus of 4 and that balances it out.
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if it's hard to understand tell me and I'll explain it in the simpler way

Answer 2

2

Explanation:

There are four 11-year olds and x amount of 14-years old.

We are given the average of this group of 11 and 14 year olds is 12.

This gives us the following equation to solve for x:

`(4(11)+x(14))/(4+x)=12`

Doing some simplifying on the left and writing 12 as 12/1 on the right because I'm going to cross-multiply in the step to follow:

`(44+14x)/(4+x)=(12)/(1)`

Cross multiplying:

`1(44+14x)=(4+x)(12)`

Distribute:

`44+14x=48+12x`

Subtract 12x on both sides:

`44+2x=48`

Subtract 44 on both sides:

`2x=4`

Divide both sides by 2:

`x=2`

There are two 14-year olds.

Let's confirm.

You have four 11 year olds and two 14 years old.

So you have:

11,11,11,11,14,14

We want to find the average of this set of numbers.

You add the numbers and divide by the number of numbers.

`(11+11+11+11+14+14)/(6)=(72)/(6)=12`

This is the average the problem wanted us to obtain so the work we did above is correct.