Name: ___________________

Date:___________________

kwizNET Subscribers, please login to turn off the Ads!
Email us to get an instant 20% discount on highly effective K-12 Math & English kwizNET Programs!

Grade 8 - Mathematics
2.9 Compound Proportion

Example:
10 men can lay a road 75 Km. long in 5 days. In how many days can 15 men lay a road 45 Km. long.

Solution:
Let x be number of days.
Ratio of days = 5:x.
Number of men is inversely proportional to number of days.
So inverse of ratio of men = 15:10 = 3:2.
Length of road is directly proportional to number of days.
Therefore, Ratio of lengths = 75:45 = 5:3
5:x = 3*5:2*3
x*3*5 = 5*2*3
x = (5*2*3)/(3*5)
x = 2.
Number of days required = 2 days.


Directions: Solve the following problems. Also write at least ten examples of your own.
Q 1: The dorm charges $6300, for 35 students for 24 days , in how many days will the dorm charges be $3375 for 25 students.
16 days
17 days
18 days
15 days

Q 2: 24 men working at 8 hours per day can do a piece of work in 15 days. In how many days can 20 men working at 9 hours per days do the same work.
16 days
18 days
15 days
17 days

Question 3: This question is available to subscribers only!

Question 4: This question is available to subscribers only!


Subscription to kwizNET Learning System costs less than $1 per month & offers the following benefits:

  • Unrestricted access to grade appropriate lessons, quizzes, & printable worksheets
  • Instant scoring of online quizzes
  • Progress tracking and award certificates to keep your student motivated
  • Unlimited practice with auto-generated 'WIZ MATH' quizzes
  • Child-friendly website with no advertisements


© 2003-2007 kwizNET Learning System LLC. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. For permission, contact info@kwizNET.com
For unlimited printable worksheets & more, go to http://www.kwizNET.com.