Find the average of 1/4 and 1/5
2007-12-03 06:11:58 · 11 answers · asked by Bride2Be 4 in Science & Mathematics ➔ Mathematics
average = (a+b)/2, right? so we do this
(1/4 + 1/5) /2, work on numerator, LCD is 20
(5/20 + 4/20) /2, combine numerator
(9/20) / (2/1), we wrote the denominator this way, so we flip it over, or
(9/20) * (1/2), since div = mult by reciprocal, right
( (9*1)/(20*2)) or (9/40).
Done.
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2007-12-03 06:14:27 · answer #1 · answered by Anonymous · 0⤊ 0⤋
1/4 + 1/5/2
(1/4 x 1/5) + (1/5 x 1/4) in order to find a common denominator
1/20 + 1/20 = 2/20
2/20 reduced = 1/10
1/10 divided by 2 to average
1/10 x 1/2 = 1/20
2007-12-03 06:19:56 · answer #2 · answered by bettyrubleinspurs 4 · 0⤊ 0⤋
convert your 1/4 to 5/20 and your 1/5 to 4/20. Then add 5/20 + 4/20 and you get 9/20. Divide that by 2, you get 9/40.
2007-12-03 06:19:20 · answer #3 · answered by wyld_fyre 2 · 0⤊ 0⤋
To find an average you add your numbers together, then divide the sum by the original number of numbers you had.
1/4 + 1/5= 5/20+4/20 = 9/20
Divide by two.
9/20 / 2= 9/20x1/2= 9/40
And that's your average.
2007-12-03 06:22:16 · answer #4 · answered by MainelyAs11 2 · 0⤊ 0⤋
Add the numbers up, divide by the number of numbers you have.
1/4 + 1/5 = 9/20
9/20 / 2 = 9/40
2007-12-03 06:15:00 · answer #5 · answered by Hiker 4 · 0⤊ 0⤋
1/4 (5/20) + 1/5 (4/20) = 9/20
9 / 20 divided by 2 = 9 / 40
9 / 40
2007-12-03 06:16:02 · answer #6 · answered by Luke 2 · 0⤊ 0⤋
Definition of Average
Average is the number that is found by dividing the sum of data by the number of items in the data set. It is also called the mean.
Solved Example on Average
The list below shows Andy's scores on five math tests. Find his average score.
35, 45, 61, 59, 73
Choices:
A. 50
B. 59
C. 54.6
D. 68.25
Correct Answer : C
Solution:
Step 1: To find the average score, add all the scores and divide the sum by 5.
Step 2: Andy's average math score is 54.6.
2007-12-03 06:22:04 · answer #7 · answered by BluGrrl 3 · 0⤊ 0⤋
(1/4 + 1/5)/2
= (5/20 + 4/20)/2
= 9/40
=0.225
2007-12-03 06:15:53 · answer #8 · answered by R L 2 · 0⤊ 0⤋
Average of two numbers is their sum, divided by 2.
You want:
(1/4 + 1/5)
---------------
...... 2
To add the fractions in the numerator, find a common denominator of 20:
(5/20 + 4/20)
------------------
........ 2
So that is:
9/20
-------
.. 2
The final answer is 9/40
2007-12-03 06:16:03 · answer #9 · answered by Puzzling 7 · 0⤊ 0⤋
the average of 1/4 and 1/5 can be found by adding them, then dividing by the number of terms added (in this case, two).
This shows that the average will be 0.225.
2007-12-03 06:15:58 · answer #10 · answered by evenstar03 2 · 0⤊ 0⤋