Julia spends 3 minutes running for every 5 minutes lifting weights. Which of the following could be how Julia spends time at the gym? (Choose 2 answers)
a. Running for 6 minutes, then lifting weights for 10 minutes.
b. Running for 9 minutes, then lifting weights for 15 minutes.
c. Running for 15 minutes, then lifting weights for 25 minutes.
d. Running for 20 minutes, then lifting weights for 30 minutes.