In this section, you will learn solving word problems by converting the given rate to unit rate.
First let us understand what is unit rate.
Definition of Unit Rate :
Unit rate compares the given amount to one unit of another measure
(or)
The ratio between the given value and 1
(or)
Comparing the given amount or value to 1
Examples :
1. If 8 dolls are made in 4 days,
then number of dolls made in 1 day = 2
2. If David earns $180 in 9 hours,
then number of dollars earned by him in 1 hour = $ 20
3. If there are 16 cups in 4 quarts,
then the number of cups in 1 quart = 4
From the above picture, we can get the following unit rates related liquid measurements.
1 gallon = 16 cups
1 gallon = 8 pints
1 gallon = 4 quarts
1 quart = 2 pints
1 quart = 4 cups
1 pint = 2 cups
Problem 1 :
In a business, if A can earn $7500 in 2.5 years, find the unit rate of his earning per month.
Solution :
Given : Earning in 2.5 years = $7500
1 year = 12 months
2.5 years = 2.5 ⋅ 12 = 30 months
Then, earning in 30 months = $7500
Therefore, earning in 1 month = 7500 / 30 = $250
So, the unit rate of his earning per month is $250.
Problem 2 :
If David can prepare 2 gallons of juice in 4 days, how many cups of juice can he prepare per day ?
Solution :
No of gallons of juice prepared in 4 days = 2 gallons
1 gallon = 16 cups
So, no. of cups of juice prepared in 4 days = 2 ⋅ 16 = 32 cups
Therefore, David can prepare 32 cups of juice in 4 days.
Then, no. of cups of juice prepared in 1 day = 32 / 4 = 8
So, David can prepare 8 cups of juice in 1 day.
Problem 3 :
If John can cover 360 miles in 3 hours, find the number of miles covered by John in 1 minute.
Solution :
No of miles covered in 3 hours = 360
Then, no. of miles covered in 1 hour = 360 / 3 = 120
1 hour = 60 minutes
So, no. of miles covered in 60 minutes = 120
Then, no. of miles covered 1 minute = 120 / 60 = 2
So, John can cover 2 miles in 1 minute.
Problem 4 :
75 basketballs cost $1,143.75. Find the unit rate in price per basketball.
Solution :
Given : 75 basketballs cost $1,143.75
Then, price of one basket ball = 1143.75 / 75 = 15.25
So, the unit rate in price per basket ball is $ 15.25
Problem 5 :
In 36.5 weeks, Miguel raised $2,372.50 for cancer research. How was his unit rate in price per week ?
Solution :
Given : Miguel raised $2, 372.50 in 36.5 weeks
Then, amount raised in one week = 2372.5 / 36.5 = 65
So, the unit rate in price per week was $65.
Problem 6 :
A person can cover a distance of 84 miles in 4 gallons of fuel. If he has 2.5 gallons, how many miles can he cover ?
Solution :
Given : 84 miles can be traveled in 4 gallons.
Then, no. of miles traveled in 1 gallon = 84 / 4 = 21
Therefore, no. of miles traveled in 2.5 gallons is
= 21 ⋅ 2.5
= 52.5
So, 52.5 miles traveled in 2.5 gallons of fuel.
Problem 7 :
If a person drinks 8 cups of apple juice per month, how many gallons will he drink in one year?
Solution :
Given : 8 cups in one month
1 year = 12 months
So, no. of cups in 1 year = 8 ⋅ 12 = 96 cups
1 gallon = 16 cups
Therefore, no. of gallons in 1 year = 96 / 16 = 6
So, he will drink 6 gallons of apple juice in 1 year.
Problem 8 :
My David earns $416 in 8 hours. How much does earn in 2.8 hours ?
Solution :
Given : Earning in 8 hours = $ 416
Earning in 1 hour = $ 52
Earning in 2.8 hours = 52 ⋅ 2.8 = 145.6
So, Mr. David will earn $145.6 in 2.8 hours.
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WORD PROBLEMS
Word problems on simple equations
Word problems on linear equations
Word problems on quadratic equations
Area and perimeter word problems
Word problems on direct variation and inverse variation
Word problems on comparing rates
Converting customary units word problems
Converting metric units word problems
Word problems on simple interest
Word problems on compound interest
Word problems on types of angles
Complementary and supplementary angles word problems
Trigonometry word problems
Markup and markdown word problems
Word problems on mixed fractrions
One step equation word problems
Linear inequalities word problems
Ratio and proportion word problems
Word problems on sets and venn diagrams
Pythagorean theorem word problems
Percent of a number word problems
Word problems on constant speed
Word problems on average speed
Word problems on sum of the angles of a triangle is 180 degree
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Ratio and proportion shortcuts
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Domain and range of rational functions with holes
Graphing rational functions with holes
Converting repeating decimals in to fractions
Decimal representation of rational numbers
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L.C.M method to solve time and work problems
Translating the word problems in to algebraic expressions
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Remainder when 17 power 23 is divided by 16
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Sum of all three four digit numbers formed using 1, 2, 5, 6