Civil Engineering - Water Supply Engineering - Discussion

Discussion Forum : Water Supply Engineering - Section 7 (Q.No. 5)
5.
The population of a city in 2000 is 50,000. The average increase in population over last 8 decades is 7500 and average incremental increase during 8 decades is 750. The population of the city based on incremental method, in the year 2020 will be
55,000
60,500
66,500
72,500
76,500
Answer: Option
Explanation:
No answer description is available. Let's discuss.
Discussion:
16 comments Page 1 of 2.

Jajhjiik said:   1 decade ago
According to incremental increase method, yn = yo+nr+n(n+1)/2xk.

yo = Initial population n = No of decades k = net incremental increase.

r = avg increase in population.

So, y 2020 = 50000+7500x2+3x750 = 67250.

Answer given is wrong.

Grace said:   9 years ago
By incremental increase method, Pn = P + n (Average Increase+ Incremental Increase)
Given: P=50,000 ; n=2 ; Average Increase = 7500 ; Incremental Increase = 750,
Hence P2=50000+2(7500+750) = 66,500.

Ghosh said:   8 years ago
Yes 67250 is the right answer here.

Satish Verma said:   7 years ago
67250 is the right option.

Jignesh said:   7 years ago
@Jajhjiik.

Can you please explain how came 2 ad 3?

Girma B. said:   7 years ago
The final answer is 67250.

Subhasmita patra said:   6 years ago
The formula for geometrical increase method is;

P(1+IG/100)^n.

P= population.
IG= average percentage per decade.
n= no of decad.

So, Pn=50000(1+20/100)^2.
= 72000.

Mahesh sinh said:   6 years ago
Pn = P+n(Ia+Iinc),
Pn = 5000+2(7500+750).
= 66500.
(2)

Prashanth said:   5 years ago
@Jajhjiik.

How it came 3? please explain sir.
(1)

Renis@Gajipara said:   5 years ago
The population of the city based on the incremental method, in the year 2020.

i = 7500 & r = 750.
Pn = P + (i+r)n.
= 50000 + (7500+750)*2.
Pn = 66500.

Where,
P = Present population in 2000.
i = avg. increase in population.
r = avg. incremental increase.
n = Number of decades.
(10)


Post your comments here:

Your comments will be displayed after verification.