72 - 45 = 27
Samantha took 27 coins. She took 3 dimes, 2 nickels and all but 1 penny, so 7 pennies. This is 12 coins. The rest must be quarters. 27 - 12 = 15 quarters.
15 x 0.25 = 5.25
The value of the quarters that Samantha took is $3.75.
Hope this helps!