A bullet loses nth fraction of its velocity while passing through a sandbag. The minimum number of sandbags required to arrest the bullet is?

the velocity after first bag = v- v/n = v(n-1)/n
the velocity after secnod bag = v(n-1)/n- v(n-1)/n^2 = v(n-1)/n(n-1)/n = v(n-1)²/n²

if n=1, means velocity loses complete velocity then 1 bag required.