A chef planing for a large banquet thinks that 2 out of every 5 dinner guests will order his soup appetizer he expects 800 guest at the banquet use equivalent ratios to estimate how many cups of soup he should prepare

320 cups

Step-by-step explanation:

In this question, we are asked to provide an estimate of the number of cups of soup to be prepared by a chef.

We know that 2 out of 5 guests would order the food and thus we need to prepare for this. Now, since 2 are ordering, it means 3 are not ordering.

The ratio of the number of guest ordering to the number of guest not ordering is 2:3

Now, we are expecting 800 guests. So we use ratio to divide and know the number of cups we are to prepare for. Let’s do this!

The total ratio is 5, to get the number , we simply put 2/5 * 800 = 320 guests

This means that the potential number of orders is 320 orders and thus the number of cups to prepare should be 320 cups

step-by-step explanation:

30% of $420 is 0.30($420) = $126 and $420 + $126 = $546.

or, 130% of $420 is 1.3($420) = $546.

notice that this is not the $600 original list price with which we started.

why doesn't this work?

the method does not work because 30% of $420 is not the same amount as the 30% of $600. it may seem obvious when stated this way, but it is a very common error made on problems of this type. we cannot just use the same percent and get back to the original amount because we are taking that percent of a different value.

to work problems of this type correctly, it is generally best to write an equation for the situation and then solve.

example: since (100% – 30%)(original price) = (sale price)

70% of the   (original price) is $420.

0.7x   = 420

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x = 600

the original cost was $600.

we may also solve this problem using the two-step method. working the problem in two steps requires us to use more algebra skills. we have to know that x = 1x (identity property of multiplicationtext annotation indicator) and that 1x – 0.3x = 0.7x (subtracting like terms). then we solve the problem as follows:

(original price) – 30%(original price) = sale price

x – 0.3x = 420

0.7x = $420

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x = 600

the original cost was $600.  

note that with both of the above methods we do obtain the correct original amount.

example: after a 5% pay raise, hermione is earning $22,680 per year. what was she earning before the pay raise?

105% of (original salary) = current salary

1.05x = 22,680

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x = 21,600

hermione earned $21,600 per year before the pay raise.

this is an example so maybe you will get how to at least do it!

step-by-step explanation: