Final answer:
To raise the coolant level from 12 to 20 inches in the radiator, you multiply the 8-inch difference by the rate of 0.8333 pints per inch, which approximately requires an additional 6.6664 pints. The closest answer is 10 pints (Option B).
Step-by-step explanation:
The question is asking how many pints of coolant would it take to fill the radiator from the 12-inch mark to the 20-inch level. Since Alex filled the radiator with 10 pints to reach the 12-inch mark, it's assumed that the relationship between pints added and the height of the coolant in the radiator is linear.
To fill the radiator to the 20-inch level, we need to determine the number of pints per inch. Since 10 pints filled it to 12 inches, this works out to approximately 10 pints / 12 inches = 0.8333 pints per inch. So for every additional inch, it takes roughly 0.8333 pints.
Now, from 12 inches to 20 inches is an 8-inch difference (20 - 12 = 8). To find out how many pints we need for those 8 inches, we multiply 8 inches by 0.8333 pints per inch, giving us 6.6664 pints. Although a pint is an integer value, the closest match from the provided options, based on these calculations, is Option B) 10 pints.