Question

contains 200 grams of oil that's 30 degrees celsius
they add 100 grams of that oil that's 70 degrees celsius
the balance temperature is 40 degrees celsius
what's the specific heat capacity
of the oil

Answer 1

It can't happen if you are adding the same oil and the specific heat is constant from 30 to 100 C.

The 200 g of cold oil would gain 200*10*C calories and the 100 g of hot oil would lose 100*30C calories, where c is the specific heat.

They have to be equal.