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If the average of 5 numbers is 36 and the average of four
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08 Dec 2017, 20:57
08 Dec 2017, 20:57
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If the average of 5 numbers is 36 and the average of four of those numbers is 34, then what is the value of the fifth number?
A. 2
B. 34
C. 35
D. 36
E. 44
A. 2
B. 34
C. 35
D. 36
E. 44
Drill 4
Question: 6
Page: 532
Question: 6
Page: 532
Re: If the average of 5 numbers is 36 and the average of four
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29 Dec 2017, 16:38
29 Dec 2017, 16:38
Expert Reply
Explanation
Use the Average Pie to solve each part of the problem. If the average of 5 numbers is 36, then the sum of those numbers is 180. If the average of four of the numbers is 34, then the sum of those numbers is 136.
new.jpg [ 13.49 KiB | Viewed 6020 times ]
If five numbers add up to 180 and four of those five numbers add up to 136, then the fifth number is the difference between those two sums: 180 – 136 = 44. If you picked choice (A), you found the difference between the two averages, not the fifth number. If you picked choice (C), you found the average of the averages. If you picked either choice (B) or choice (D), you resolved for the average after determining the sum.
Use the Average Pie to solve each part of the problem. If the average of 5 numbers is 36, then the sum of those numbers is 180. If the average of four of the numbers is 34, then the sum of those numbers is 136.
Attachment:
new.jpg [ 13.49 KiB | Viewed 6020 times ]
If five numbers add up to 180 and four of those five numbers add up to 136, then the fifth number is the difference between those two sums: 180 – 136 = 44. If you picked choice (A), you found the difference between the two averages, not the fifth number. If you picked choice (C), you found the average of the averages. If you picked either choice (B) or choice (D), you resolved for the average after determining the sum.
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If the average of 5 numbers is 36 and the average of four
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19 Jan 2020, 07:13
19 Jan 2020, 07:13
2
sandy wrote:
If the average of 5 numbers is 36 and the average of four of those numbers is 34, then what is the value of the fifth number?
A. 2
B. 34
C. 35
D. 36
E. 44
A. 2
B. 34
C. 35
D. 36
E. 44
Drill 4
Question: 6
Page: 532
Question: 6
Page: 532
Let the five numbers be a, b, c, d, and e
The average of 5 numbers is 36
We can write: \(\frac{a+b+c+d+e}{5}=36\)
Multiply both sides by 5 to get: \(a+b+c+d+e=180\)
The average of four of those numbers is 34
We can write: \(\frac{a+b+c+d}{4}=34\)
Multiply both sides by 4 to get: \(a+b+c+d=136\)
What is the value of the fifth number?
At the moment we have two equations:
\(a+b+c+d+e=180\)
\(a+b+c+d=136\)
When we subtract the bottom equation from the top equation we get: \(e = 44\)
Answer: E
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