Same problem statement for $1,2,3,4,5,6,7,8,9,10$

Suppose that a $32$M X $64$ main memory is built using $512$K X $8$ RAM chips and memory is word addressable,

$1.$ How many RAM chips are there per bank?

$4$

$8$

$12$

$16$

$18$

$22$

$24$

$32$