Questions

The first step in the refining of petroleum is distillation i.e,  the fractionation of crude oil in atmospheric and vacuum distillation towers.

The first process petroleum refinery is known as distillation. In this process, crude oil is heated and fed into a distillation column. As the temperature of the crude oil in the distillation column rises, the crude oil separates itself into different components, called "fractions." The fractions are then captured separately. Each fraction corresponds to a different type of petroleum product, depending on the temperature at which that fraction boils off the crude oil mixture.

Here the puzzle follows the logic that

Right side number = sum of the number on the left side and the previous number on the left side

=> 6 = 4+2

=> 10 = 6+4

=> ? = 16+10 = 26.

Except 142 all are divisible by number '7'.