Multiple choice 40 U.S. gallons when expressed in imperial gallons is equal to 33 49 56 63 Reveal answer Fill a bubble to check yourself A Correct answer Explanation 40 US gallons converted to imperial gallons: 40 x 3.785 / 4.546 = 33.3 imperial gallons. The answer 33 (rounded) is correct. 49, 56, and 63 are incorrect. Imperial gallons are larger, so you get fewer imperial gallons.