The johnsons pay $9.95 a month plus $.035 per min for local phone service. last month, they paid $12.75. how many minutes of local calls did they make?

Johnson's made 80 minutes of local calls

Step-by-step explanation:

The Johnson's pay $9.95 a month plus $0.035 per min for local phone service.

i.e. if Johnson's makes a local phone call for m minutes in a month then, monthly payment they have to make equals

$(9.95+0.035m)

Last month, they paid $12.75.

Let they made m minutes of local calls

then, 9.95+0.035m=12.75

0.035m=12.75-9.95

0.035m=2.8

m=2.8/0.035

m=80

Hence, Johnson's made 80 minutes of local calls

80π/3 or about 83.775

step-by-step explanation:

since a cone is 1/3 of a cylinder, we need to find the base's area. since area = πr^2, we get 16π. then, multiplying this by 5, we get 80π. dividing by 3, since the cone's volume is 1/3 of that of a cylinder's, we get 80π/3.

hope this !