Final answer:
Brandon's average rate of solving problems on the math test was 0.25 problems per minute, calculated by dividing the total number of problems solved, which was 12 1/2 or 25/2 after conversion, by the 50 minutes taken.
Step-by-step explanation:
To calculate Brandon's average rate of solving problems per minute on his math test, we can use the formula for rate which is the number of problems solved divided by the time taken to solve them. Brandon solved 12 1/2 problems in 50 minutes.
To find the average rate per minute, we will first convert the mixed number (12 1/2) into an improper fraction. The mixed number 12 1/2 can be converted to an improper fraction by multiplying the whole number by the denominator, adding the numerator, and then placing that result over the original denominator, like this:
12 × 2 + 1 = 24 + 1 = 25
So, 12 1/2 becomes 25/2.
Next, we divide the number of problems by the number of minutes to find the rate:
(25/2) problems ÷ 50 minutes = 25 problems ÷ 100 minutes = 0.25 problems per minute
Therefore, answer (a) is correct: Brandon solved an average of 0.25 problems per minute.