Two gases NO & O2 were introduced at the twoends of a 1m long tube simultaneously.At what distance from NO gas end, Brownfumes will be seen?

Let y cm be the distance from NO gas end.
Then, distance from O₂ end = (100 - y) cm

Molecular mass of NO = 14.0 + 16.0 = 30
Molecular mass of O₂ = 16.0 × 2 = 32

y/(100 - y) = √(32/30)
y/√(32/30) = 100 - y
y {[ 1/√(32/30)] + 1} = 100
y = 100 / {[ 1/√(32/30)] + 1}
y = 50.8

Distance from NO gas end = 50.8 cm