In the following equations, t represents time in hours and m represents mass in mf. Which of them (if any) would have a mass less than 50 mg after 2 hours? Select all that apply.

a. y = 100 (0.5) ^x

b. y = 500 (0.3) ^x

c. y = 80 (2) ^x

d. y=10 (1.2) ^x

e. y=30 (1.5) ^x

f. y=80 (0.2) ^x

g. y=100 (2) ^x

a, b, d and f

Step-by-step explanation:

To find which equation will have a a mass less than 50 mg after 2 hours, we just need to use the value of x = 2 and then verify if the values of y are less than 50:

a. y = 100 * (0.5) ^2 = 25 - > apply

b. y = 500 * (0.3) ^2 = 45 - > apply

c. y = 80 * (2) ^2 = 320 - > doesn't apply

d. y = 10 * (1.2) ^2 = 14.4 - > apply

e. y = 30 * (1.5) ^2 = 67.5 - > doesn't apply

f. y = 80 * (0.2) ^2 = 3.2 - > apply

g. y = 100 * (2) ^2 = 400 - > doesn't apply