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
Discussion:
16 comments Page 1 of 2.
Thasni Kalam said:
3 years ago
According to Incremental increase method;
P=p+nx+n(n+1)/2*y
P - popln after n decades from the present.
p - present population
x - avg increase of population of known decades
y - avg of incremental increase of the known decades.
Then substitute these values in eqn
Here we want to find the 2020th population calculating from 2000-2020 n=2 decades
P=50000+2*7500+2(2+1)/2*750 = 67250
So, the correct answer is 67250.
P=p+nx+n(n+1)/2*y
P - popln after n decades from the present.
p - present population
x - avg increase of population of known decades
y - avg of incremental increase of the known decades.
Then substitute these values in eqn
Here we want to find the 2020th population calculating from 2000-2020 n=2 decades
P=50000+2*7500+2(2+1)/2*750 = 67250
So, the correct answer is 67250.
(9)
Aakriti pandey said:
3 years ago
What rate of supply would you recommend, for a town with a population of 50,000?
Anyone answer me.
Anyone answer me.
(2)
Smith said:
5 years ago
Thanks all for eplaining the answer.
(1)
Noini said:
5 years ago
Avg increase is 7500 calculated for 8 decades.
Then the total increase in population from 1930 is 7500x8=60000. If increase itself is 60000, what is the actual population in 1920 initially then? How can the population in 2000 be very less=50000?
Please anyone explain.
Then the total increase in population from 1930 is 7500x8=60000. If increase itself is 60000, what is the actual population in 1920 initially then? How can the population in 2000 be very less=50000?
Please anyone explain.
(2)
Anirban Roy said:
5 years ago
Yes, you are right @Pooja. So,
Pn = 55000 + 2 * 7500+(2 * 3÷2) * 750 = 67250.
Pn = 55000 + 2 * 7500+(2 * 3÷2) * 750 = 67250.
(1)
Pooja said:
5 years ago
Pn = Po + nx + [(n(n+1))/2]*y.
n = no Of decades,
x = avg increase in population,
y = avg. incremental increase,
Po = initial population.
n = no Of decades,
x = avg increase in population,
y = avg. incremental increase,
Po = initial population.
(2)
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.
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)
Prashanth said:
5 years ago
@Jajhjiik.
How it came 3? please explain sir.
How it came 3? please explain sir.
(1)
Mahesh sinh said:
6 years ago
Pn = P+n(Ia+Iinc),
Pn = 5000+2(7500+750).
= 66500.
Pn = 5000+2(7500+750).
= 66500.
(2)
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.
P(1+IG/100)^n.
P= population.
IG= average percentage per decade.
n= no of decad.
So, Pn=50000(1+20/100)^2.
= 72000.
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