For his long distance phone service, Keith pays a $5 monthly fee plus 9 cents per minute. Last month, Keith's long distance bill was $21.02. For how many minutes was Keith billed?

178 minutes

21.02 x 100 = 2102

2102 - 500 = 1602

1602 / 9 = 178

d. millimeters per hour.

step-by-step explanation:

we are given that,

carlo used a rain gauge to measure the amount of water his lawn is receiving from the sprinklers.

since, according to the options, we see that,

water cannot be measured by 'miles per hour', 'meters per second' and 'grams per seconds'.

we get that, the water can be measured by 'millimeters per hour'.

hence, the appropriate rate for describing the amount of water is 'millimeters per hour'.