When the temperature of a gas in a vessel is increased by 1C then the pressure is increased by 0.5%. what will be its initial temperature?

P V = n R T

assume V constant
P = (nR/V) T
dP = (nR/V) dT
dP/P = (nR/V) dT/P = dT/T
but dP/P = .005
so
.005 = 1/T
T = 200