Let x be the number of 2-cent stamps. We know that the 41-cents stamp are four times as many, so they are 4x. The total is thus worth
[tex] 0.02x + 0.41\cdot 4x = 33.20 \iff 0.02x + 1.64x = 33.20 \iff 1.66x = 33.20 \iff x = \dfrac{33.20}{1.66} = 20 [/tex]
So, Hector bought 20 2-cents stamps, and 80 41-cents stamp.