1)a vertical cylinder closed from both ends is equipped with an easily moving piston dividing the volumes in 2 parts each containing one mole of air .In equilibrium at T=300k the ratio of the volumes f the upper and lower parts is 4.the temp at which the rati will be 3 is-

a)320

b)420

c)480

d)500 

in the first case V1/V2  = 4

therefore V1  = 4 V2

in the second case  V1/ V2 = 3

therefore V1 = 3V2

using v1/t1  = v2 /t2

here v1 = 4V1,  v2 = 3V2, t1 = 300

substituting the values we get t2 = 225

i know that ans is not matching , if any mistake in my soln then tell me, books ans are not always correct