The symbol ∩ means intersection, .i.e. you need to find the numbers that belong to both sets A and C. Those numbers might belong to the set C or not, because that is not a restriction.
Then lets find the numbers that belong to both sets, A and C.
As you see, all the perfect fourths are perfect squares, so the intersection of A and C is completed included in A. this is:
A ∩ C = C or A ∩ C = 1, 16, 81
On the other hand, the perfect cubes are:
1^3 = 1 2^3 = 8 3^3 = 27 4^3 = 81
B = {1, 8, 27, 81}
That means that the numbers 1 and 81 belong to the three sets, A, B, and C.
In the drawing you must place the number 16 inside the region that represents the intersection of A and C only, and the numbers 1 and 81 inside the intersection of the three sets A, B and C.
I took that last year and somehow still rememeber it and if you dont believe me click this link and ill show you how on search Cameron the OG and football Madness and ill give you a link to my third channel Math Nerds an help you