Question:The population of a town increases by 5% annually. If its population in 1995 was 138915, what it was in 1992 ?
A 110000
B 100000
C 120000
D 90000
/139
+ Answer
C
+ Explanation`x xx (1 + 5/(100))^3`
`= 138915 => x xx 21/20 xx 21/20 xx 21/20`
`= 138915`
`:. x = ((138915 xx 20 xx 20 xx 20)/(21 xx 21 xx 21))`
`= 120000`