Question

Samir counted 36 birds in his neighbourhood. He found doves, crows, parrot, mainas, bulbul and some other birds whos name he did not know. 2/9 were doves, 4/9 were crows, 3 birds were parrot 2 were mainas and 2 were bulbul. Find the number and fraction of birds he did not know.

Answer 1

Dear student
$$\begin{gathered} \mathrm{Total}\mathrm{number}\mathrm{of}\mathrm{birds}=36 \\ \mathrm{Number}\mathrm{of}\mathrm{doves}=\frac{2}{9}\times 36=8 \\ \mathrm{Number}\mathrm{of}\mathrm{crows}=\frac{4}{9}\times 36=16 \\ \mathrm{Number}\mathrm{of}\mathrm{parraot}=3 \\ \mathrm{Number}\mathrm{of}\mathrm{mainas}=2 \\ \mathrm{Number}\mathrm{of}\mathrm{bulbul}=2 \\ \mathrm{Birds}\mathrm{he}\mathrm{did}\mathrm{not}\mathrm{know} \\ =\mathrm{Total}\mathrm{number}\mathrm{of}\mathrm{birds}-\mathrm{Number}\mathrm{of}\mathrm{doves}-\mathrm{Number}\mathrm{of}\mathrm{crows}-\mathrm{Number}\mathrm{of}\mathrm{parraot}-\mathrm{Number}\mathrm{of}\mathrm{mainas}-\mathrm{Number}\mathrm{of}\mathrm{bulbul} \\ =36-8-16-3-2-2 \\ =5 \\ \mathrm{Fractions}\mathrm{of}\mathrm{birds}\mathrm{he}\mathrm{did}\mathrm{not}\mathrm{know}=\frac{\mathrm{Number}\mathrm{of}\mathrm{birds}\mathrm{he}\mathrm{did}\mathrm{not}\mathrm{know}}{\mathrm{Total}\mathrm{number}\mathrm{of}\mathrm{birds}}=\frac{5}{36} \end{gathered}$$
Regards