An army lost 10% of its men in war. 10% of the remaining died due to disease and 10% of the rest were declared disabled. Thus the strength of the army was reduced to 729000 active men. The original strength of the army was :

A. 1500000

B. 1000000

C. 1200000

D. 1100000

Answer: Option B

Solution(By Examveda Team)

Initial number of soldiers in the army = x
According to the question,
$$\eqalign{ & \Rightarrow {\text{x}} \times \frac{{90}}{{100}} \times \frac{{90}}{{100}} \times \frac{{90}}{{100}} = 729000 \cr & \Rightarrow x = \frac{{729000 \times 1000}}{{9 \times 9 \times 9}} \cr & \Rightarrow x = 1000000 \cr} $$

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Alternate:
10% → $$\frac{1}{10}$$
10 → 9 in war
10 → 9 in disease
10 → 9 disabled
100 → 729
729 → 729000
1 → 1000
10000 → 1000 × 1000 = 1000000