Respuesta :

Answer: x = 40

Step-by-step explanation: I know that it's tempting to try to do percentage word problems in your head but this leads to a variety of careless mistakes. So I would advise always writing out the equation by simply reading the problem from left to right and solving it from there. That way you don't have to think about the problem at all until you get to your final answer.

So for this problem we have what percent. Since we know that percent means over 100 and what means x,

what percent would be x/100.

Of means times, 36 is 36, is means equals, and 81 is 81.

So we have the equation x/100 · 20 = 8.

We can rewrite this problem as 20x/100 = 8.

To get rid of the fraction, we multiply

both sides by 100 and we have 20x = 800.

Dividing both sides by 20, you can use a

calculator to find that that x = 40.

Now let's check to see if our answer makes sense.

We have 40% of 20 is 8.

Well we know that 100% of 20 would be 20. So 40% of 20 should be alot less than 20 so 8 seems to make sense.

I have attached my own work in the image provided.

Ver imagen TheBlueFox