Lost re Word Problem Translation

Problem Solving — algebra and arithmetic (GMAT Focus Edition)
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Lost re Word Problem Translation

by afr114 » Thu Oct 17, 2013 10:35 am
I was doing the problem sets in the MGMAT: Word problems Chapter 1. On question 7, I'm having trouble figuring out the reasoning behind why the following sentence translates to 1.25V = S:

They sold 25% more Standard tickets than V.I.P. tickets.

In my mind, I see this as 1.25S+V=total tickets.
Source: — Quantitative Reasoning |

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by [email protected] » Thu Oct 17, 2013 12:27 pm
Hi afr114,

Translating sentences into math formulas is a skill that is repeatedly tested on the GMAT, so it's one worth practicing.

For this translation, I'll use the same variables that you used:

V = Number of VIP tickets
S = Number of Standard tickets

"The sold 25% more Standard tickets than VIP tickets"

Since we're selling more standard tickets, THAT number has to be the bigger number. So, take the smaller number (V) and add 25% to it....

V + .25V = S
1.25V = S

The equation for the TOTAL tickets is....
S + V = Total

You can "substitute" the first equation into the second....

1.25V + V = Total

Then combine terms....

2.25V = Total

And then proceed with whatever math the rest of the questions asks for.

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by afr114 » Thu Oct 17, 2013 12:41 pm
"Since we're selling more standard tickets, THAT number has to be the bigger number. So, take the smaller number (V) and add 25% to it....

V + .25V = S
1.25V = S "

I dont understand the reason why we are having the tickets equal each other.

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by [email protected] » Thu Oct 17, 2013 10:20 pm
Hi afr114,

The original sentence:

"They sold 25% more Standard tickets than VIP tickets" relates the number of VIP tickets to the number of Standard tickets. Any type of comparison between two (or more) things will require an equation or inequality symbol.

For example: "Mike is twice as old as John"

M = 2J

"There are 3 more Dogs than Cats"

D = C + 3

etc.

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by VivianKerr » Wed Oct 23, 2013 4:54 pm
For what it's worth here's some quick tips I use to deal with those obnoxious translations!

1. Write down what the question is asking.
What do the answer choices represent? The number of donuts? The cost per person for an amusement park ride? This is usually in the last sentence of the word problem.

2. Assign variables to unknown quantities. Pick variables that are logical and clear. Let's say a question is asking about the price of a child's movie ticket versus an adult's movie ticket. Choose "c" to represent the cost of one child's ticket, and choose "a" to represent to cost of one adult's ticket.

3. Go line-by-line.
Pull out the key phrases and 'translate' them from English to Math. Look for these common words and phrases. Remember to pay special attention to subtraction and division since what comes first in the sentence does not necessarily come first in the expression (i.e. "4 less than x" = x - 4).

4. Set up equation/s.
Your key phrases will tell you how the variables relate to each other. Be on the lookout for ways to set up more than one equation with the same two variables. If you have two equations with the same two variables, you can solve for either variable using Combination or Substitution.

5. Having trouble? Backsolve! If you are having a hard time setting up the equations, try to work backwards using the answer choices. If the answer choices represent the cost of the child's movie ticket, start with choice (C) and ask yourself, what if C is correct? What else has to be true? The right answer will agree with the given numbers and the relationship between the variables that is described in the question stem. This is also an excellent way to check your work! If you think you've found the correct answer, plug it in to make sure!
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