Answer:
398 stamps
Explanation:
[tex]\begin{gathered} \text{3 sets of 100 stamps}=3\times100=300\text{ stamps} \\ \text{2 sets of 20 stamps}=2\times20=40\text{ stamps} \\ \text{4 sets of 12 stamps}=4\times12=48\text{ stamps} \\ \text{1 set of 10 stamps}=1\times10=10\text{ stamps} \end{gathered}[/tex]Therefore, the total number of stamps Jordy buys:
[tex]\begin{gathered} =300+40+48+10 \\ =398\text{ stamps} \end{gathered}[/tex]