Finding how much per cent one quantity is of another quantity

Compare finding a number when a per cent of the number is known to finding the per cent of one number with that of another number.

The yield of rice is how much per cent more than that of sugarcane?

How much per cent of PAR is captured for GPP ?

How much per cent of PAR is captured for GPP ?

Total value of the quanity sold for item C is what per cent of the total value of the quantity sold for item E ?