Thanks Suman again for this lovely puzzle. The usual suspects came back with the right answer – Karan, Sid Mulherkar and Abhinav Jain (and I am not counting Suman or his daughter on this one).

Was a simple puzzle, but looks a bit daunting initially. Here is the answer copied from Sid:

Observe that the sum of the surface areas of one set of mini cuboids which do not share a face but share an edge at least one of the others will equal the sum of the areas of the other set. Let A be the area of the 8th block.

We get 88+58+126+A=148+28+46+72.

This gives A=22.

Hope you all enjoyed the puzzle!