.

Can you work all of these out in your head and/or on paper in less than a total of two minutes?

65% of 10

18% of $\displaystyle \ 16\tfrac23$

35% of 20

8% of 25

12% of $\displaystyle \ 33\tfrac13$

38% of 50

9% of $\displaystyle \ 66\tfrac23$

44% of 75