Civil Engineering - UPSC Civil Service Exam Questions - Discussion

Discussion Forum : UPSC Civil Service Exam Questions - Section 4 (Q.No. 2)
2.
If the efficiencies of BOD removal of first-stage and second-stage trickling filters are each 65.0%, then what is the overall BOD removal efficiency of these filters ?
65%
77.25%
87.75%
92.6%
Answer: Option
Explanation:
No answer description is available. Let's discuss.
Discussion:
6 comments Page 1 of 1.

Vicky Vikrant said:   9 years ago
Efficienct = 1 - (1 - n1)(1 - n2) = 1 - (1 - 0.65)(1 - 0.65) = 0.8775 i.e 87.75%.

Mayank said:   9 years ago
This can be solved by following this method.

= .65 + .65 * 0.35.

Lara said:   8 years ago
I think the answer should be C.

Sunil kumar said:   7 years ago
Yes, C option is correct.

Rahul verma said:   2 years ago
Here; n = n1+(1-n1)n2.
(1)

Naresh kumar meena said:   5 years ago
Thanks @Mayank.

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