Commonly used rates like miles per hour make it easy to understand and compare rates.
Example 1 :
Jeff hikes 1/2 mile every 15 minutes, or 1/4 hour. How far does he hike in 1 hour ?
We can use proportion to solve this problem.
Let 'a' be the number of miles covered by Jeff in 1 hour.
Then, we have
1/2 : 1/4 = a : 1
1 x 1/2 = (1/4)a
1/2 = a/4
2 = a
So, Jeff hikes 2 miles in 1 hour.
Examples 2 :
At a summer camp, the campers are divided into groups. Each group has 16 campers and 2 cabins. How many cabins are needed for 112 campers ?
First we have to find how many campers can accommodate in one cabin.
To find the number of campers accommodated in 1 cabin, we have to divide 16 by 2.
16/2 = 8
8 campers can accommodate in 1 cabin.
To find the number of cabins required for 112 campers, we have to divide 112 by 8.
112 / 8 = 14
So, 14 cabins needed for 112 campers.
Examples 3 :
If 350 miles of distance covered 7 hours, find the distance covered by 6 hours ?
First we have to find how many miles of distance covered in 1 hour.
To find the distance covered in 1 hour, we have to divide 350 by 7.
350/7 = 50
In 1 hour, 50 miles of distance covered.
In 6 hours, the distance covered = 6 x 50 = 300 miles.
Examples 4 :
Petra jogs 3 miles in 27 minutes. Find the unit rate in minutes per mile. How long would it take her to jog 5 miles ?
To find the unit rate in minutes per mile, we have to divide 27 minutes by 3 miles.
27 ÷ 3 = 27/3 = 9
Unit rate in minutes per mile = 9
That is, it takes 9 minutes to cover 1 mile of distance.
To find the time taken to cover 5 miles, we have to multiply 5 and 9
5 x 9 = 45
Therefore, it will take 45 minutes to cover 5 miles of distance.
Apart from the stuff given above, if you need any other stuff in math, please use our google custom search here.
You can also visit the following web pages on different stuff in math.
APTITUDE TESTS ONLINE
ACT MATH ONLINE TEST
TRANSFORMATIONS OF FUNCTIONS
ORDER OF OPERATIONS
Analytical geometry calculators
MATH FOR KIDS
Word problems on linear equations
Trigonometry word problems
Word problems on mixed fractrions
Ratio and proportion shortcuts
Converting repeating decimals in to fractions