KVPY Sample Paper KVPY Stream-SX Model Paper-8

In an experiment to determine the number of rats in a field, 80 rats were initially captured, marked and released. After one month, 100 rats were captured in the same field, of which 20 were previously marked ones. Based on the above observation, estimated population size of rats in the field will be

A) 160

B) 200

C) 400

D) 1600

Correct Answer: C

Solution :

\[N=\frac{{{n}_{1}}{{n}_{2}}}{{{m}_{2}}}\]

(N = population size of rats in the field)

Here, \[{{n}_{1}}=80,\]\[{{m}_{2}}=20,\]\[{{n}_{2}}=100\]

Hence, \[N=\frac{80\times 100}{20}=\frac{8000}{20}=400\]