The correct option is B 48∘C
Given that,
Initial temperature of body T1=80∘C
Temperature after 10 min T2=60∘C
Temperature of surroundings Ts=30∘C
Applying Newton's law of cooling,
ln(T1−T0T2−T0)=Kt
⇒ln(80−3060−30)=K×10...(i)
Let temperature of body after next 10 minutes be T.
So, ln(60−30T−30)=K×10...(ii)
Using equation (i) and (ii),
ln 53=ln30T−30
⇒30×3=5T−5×30
⇒T=48∘C