plug in?

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plug in?

by gkammaje » Thu Oct 30, 2008 8:12 pm
A company hired a printer to produce a total of x + 1 envelopes. The job consisted of two types of envelopes, 2¢ envelopes and 5¢ envelopes. If the company requested 3 more 2¢ envelopes than 5¢ envelopes, which of the following expressions denotes the cost, in cents, of the total x + 1 envelopes?

a)3x+1
b) (7x-2)/2
c) 11x+31
d) (7x-6)/2
e) (13x+3)/2

This was one of the questions on Princeton review CAT test. The explaination they give asks you to plug in numbers to solve it. Is there any other way to solve this?

Thanks for the help!
Source: — Problem Solving |

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by cramya » Thu Oct 30, 2008 8:19 pm
Yes there is but picking numbers will also work

Let k be the total numbe rof 5 cents enevelopes
k+3 will the number of 2 cents enevelopes

k+k+3 = x+1 (No of 5 cents + no of 2 cents = total)

k = x-2/2 (No of 5 cents envelopes)

k+3 = x-2/2 + 3
= x+4/2 (No of 2cents envelopes)


Total cost = 5(x-2/2) + 2(x+4/2)
= 7x-2/2

B)

Whats the OA?

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by gkammaje » Thu Oct 30, 2008 8:56 pm
thanks!
B is the correct answer...