Pls tell me how to solve this!

Answer:
12 seconds
Explanation:
Time taken by 50cm³ of oxygen to diffuse from pinhole
= 1 minute = 60 seconds
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[tex] \textsf{ Rate of oxygen} \sf (O_2) = \frac{50}{60} [/tex]
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Let time taken by 50cm³ of hydrogen to diffuse from pinhole = t seconds
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[tex] \textsf {Rate of hydrogen } \sf(H_2) = \frac{50}{t} [/tex]
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According to the formula
[tex] \sf \frac{Rate \: of \: hydrogen(H_2)}{Rate \: of \: oxygen(O_2) } = \sqrt{ \frac{Molar \: mass \: of \: O_2}{Molar \: mass \: of \: H_2} } [/tex]
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[tex] \large \sf \frac{50}{t} \div \frac{50}{60} = \sqrt{ \frac{\cancel{32}\small 16}{\cancel2} } \\ \\ \sf \large \frac{ \cancel{50}}{t} \times \frac{60}{ \cancel{50}} = \sqrt{16} \\ \\ \sf \large \frac{60}{t} = 4 \\ \\ \sf \large \frac{ \cancel{60} \: \small12}{ \cancel4} = t \\ \\ \large \underline{ \boxed{ \tt t = 12 \: seconds}}[/tex]
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