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!

Online Quiz (Worksheet A B C D)

Questions Per Quiz = 2 4 6 8 10

Grade 8 - Mathematics
9.39 Word Problems on Work

Example:
Method :
  • Write or get the algebraic equation.
  • Solve for the unknown.
Question: Two people can work a task in 5 hours. If the first person can complete the task alone in 9 hours. How long would it take the second person to complete the same task working alone.
Solution:
Total time in hoursFractional part of the job done in 1 hour
First Person91/9
Second Personx1/x
Together51/5

The first person takes 9 hours to complete the task working alone, implies the person completes 1/9th of the job in each hour.
Let x be the hours it takes second person to complete the task working alone, implies that the person takes 1/x of the job each hour.
Working together it takes the two people to complete the job in 5 hours. That means that each hour 1/5 of the job is getting done.
Therefore 1/9 + 1/x = 1/5
subtracting 1/9 both sides we have
1/9 + 1/x - 1/9= 1/5 - 1/9
1/x = 9/45 - 5/45
1/x = 4/45
x = 45/4 or 11 1/4
The second person takes 11 1/4 hour to finish the working alone.

Directions: Solve the following word problems and show your work. Also write at least 5 word problems of your own.
Q 1: Harry and Jim takes 18 hours to complete installing a deck. If Harry takes 30 hours to do the job alone, how many hours does it take for Jim to do the job alone?
45
50
35

Q 2: If Tom and his mom takes 6 hours to cleanup Tom's room if they work together. If it takes Tom 10 hours to cleanup his room alone, how many hours does it take his mom to clean up his room?
15
20
17

Q 3: Two mechanics work together on your car to fix it. If they work together they can fix it in 7 hours. If it takes one of the mechanics 12 hours to do the job alone, how many hours does it take the other mechanic to do the job alone?
16 4/5
13 2/5
12 3/4

Q 4: Two people can work a task in 10 hours. If the first person can complete the task alone in 20 hours. How long would it take the second person to complete the same task working alone.
10 hours
20 hours
5 hours

Question 5: This question is available to subscribers only!

Question 6: This question is available to subscribers only!


Subscription to kwizNET Learning System 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
  • Choice of Math, English, Science, & Social Studies Curriculums
  • Excellent value for K-12 and ACT, SAT, & TOEFL Test Preparation
  • Get discount offers by sending an email to discounts@kwiznet.com

Quiz Timer