0 if you add the thickness to the underside of the tank
<h3>
<u>QU</u><u>ESTION</u><u>:</u></h3>
WHAT IS THE PRODUCT OF: 7.21 x 4.2
PLEASE--
<h3>SOLUTION AND ANSWER:</h3>

THEREFORE, <em><u>30.282</u></em> IS THE PRODUCT
HOPE THIS HELP YOU! HAVE A NICE DAY!
~kimtaetae92~
NOTE: Kindly see this answer from brainly app if you are in web to see the displayed formats here.
Answer is B (hope this helps!)
1st. is definitely 150.
2nd. is a i think
3rd. is 100