Question 155523
You could make a table with all possible outcomes thus:

THERE ARE 32 POSSIBLE OUTCOMES (2^5=32).
EXACTLY 3 HEADS ARE 10 OUT OF 32 [AS SHOWN BELOW] 0R 10/32=31.25% OF THE TIME.

H H H T T
H H T H T
H T H H T
T H H H T
H H T T H
H T T H H
T H T H H
T T H H H
T H H T H
H T H T H