The population of India in 1998 was `800` million. What will be the population in `2000` and `2100` if there is no change in the present growth rate which is `25` per `1000` per year?

Explanation

The equation for first order can be mofified as:
`k = (2.303)/(t)log.(a)/(a-x)`
Growth rate `= (2.303)/("Time"(t))log.("Present population", P_(0) ("for" 2000))/("Population" (P_(t)) "at time t" ("for" 1998))`
(a) `(25)/(1000) =(2.3030)/((2.303 - 1998)) log.(P_(0))/(P_(t))`
`log.(P_(0))/(P_(t)) = (25 xx 12)/(1000 xx 2.303) = 0.1303`
`(P_(0))/(P_(t)) = "Antilog" (0.1303) = 1.350`
`P_(0) = 1.350 xx P_(t) = 1.350 xx 800 million = 1080 million`
Population in 2000 year `= 1080 million`
(b) `(25)/(1000) = (2.303)/((2100-1988)) = log.(P_(0)("for" 2100))/(P_(t)("for" 1988))`
`log.(P_(0))/(P_(t)) = (25 xx 112)/(1000 xx 2.303) = 1.2158`
`(P_(0))/(P_(t)) = 1.644`
`P_(0) = 1.644 P_(t) = 1.644 xx 800 million = 1315.2 million`
`:.` Population in `2100 = 1315.2 million`