The Math Forum

Ask Dr. Math - Questions and Answers from our Archives
Associated Topics || Dr. Math Home || Search Dr. Math

Touring China and Thailand

Date: 5/30/96 at 1:49:34
From: Eric Liu
Subject: How long is the tour?

        Hi! This is Cristian. I have two math questions:
1. A tour to China is twice as long as a tour to Thailand. If both 
tours last 5 weeks and 1 day altogether, how long is the tour to 

2. The total of the ages of Janet and Pam is 21 years and 1 month. If
Janet is 7 months older than Pam, how old is Pam?
Thank you very much. 

Date: 6/5/96 at 18:9:44
From: Doctor Jodi
Subject: Re: How long is the tour?

Hi there!  Thanks for your questions!

Let's say that the tour to Thailand lasts  x days.  Then the tour to 
China lasts twice as long, 2x.

Now, since there are 7 days in a week, together the tours last  
(5 weeks * 7 days/week) + 1 = 36 days

The tours last

36 days = 2x     +    x
          China       Thailand

Does this make sense so far?

Now, 2x + x = 3x, so we can rewrite this as

36 = 3x

Now we divide each side by 3 to get

36    3x    
--  = -- 
3     3

which we can rewrite as

12 = x

Now we have to go back up to our list to remind ourselves that x 
stands for the number of days in Thailand.  But we are looking for the 
number of days spent in China, which is 2x or 24.  So the answer is 24 
days. Does that make sense?

The next problem is similar so I'll just get you started on it:

Pam = x months
Janet = x + 7 months

Total age = 
             21 years + 1 month =   
            (21 years * 12 months/year) + 1 month = 253 months

             253 = x + x + 7

Can you finish this problem?  Let us know if you need more help.

-Doctor Jodi,  The Math Forum
 Check out our web site!   
Associated Topics:
Elementary Word Problems

Search the Dr. Math Library:

Find items containing (put spaces between keywords):
Click only once for faster results:

[ Choose "whole words" when searching for a word like age.]

all keywords, in any order at least one, that exact phrase
parts of words whole words

Submit your own question to Dr. Math

[Privacy Policy] [Terms of Use]

Math Forum Home || Math Library || Quick Reference || Math Forum Search

Ask Dr. MathTM
© 1994- The Math Forum at NCTM. All rights reserved.