Karas jug contains 2 quarts of apple cider. she fills 8 mugs with cider. each mug can hold six three fourths of fluid ounces. how many fluid ounces are left in the jug

So first of all you need to know that in 1 quart there is 31.9995 ounces so since shes says there is 2 quarts lets do the math:)
31.9995 x 2 = 63.999 ounces 
now she says she took 8 mugs and filled them up each with 6 and 3/4 ounces. lets do the math:)
6 and 3/4 x 8 = 30 ounces
now lets subtract that from our 2 quarts or 63.999 ounces 
63.999 - 30 = 33.999 
so we have 33.999 fluid ounces left in the jar:)
hope this helps lol