We have PV=nRT
As total no of gas molecules in the bulbs would remain constant,
we have n1+n2=n′1+n′2
P0VRT0+P0VRT0=P.VRT+PVRT0
i.e. 2P0T0=P(1T+1T0)
Hence new pressure P=(2TT+T0)⋅P0
Here P0=76 cm of Hg (initial pressure), T0=0∘=273 K
T=62∘C=335 K
∴P=2×335(273+335)×76=83.75 cm of Hg.