The tutor charges $40 plus $30 for each student in the group. Today the tutor has s students and charges a total of $220. How many students does the tutor have?

6 students

Step-by-step explanation:

Given data

Base charge= $40

charge per student = $30

We are told that for s number of student the tutor charged 220

The expression for the tutor's charges is given as

y= 40+30s

Therefore for y= 220, let us find s, the number of students

220=40+30s

220-40= 30s

180=30s

divide both sides by 30

s= 180/30

s= 6

Hence there are 6 students

1: 3 ratio of the volume of the cone to the volume of the cylinder

Step-by-step explanation:

Volume of cone(V) is given by:

where, r is the radius and h is the height of the cone.

Volume of cylinder(V') is given by:

where,  r' is the radius and h' is the height of the cylinder.

As per the statement:

A cylinder and a cone have congruent heights and radii.

⇒r = r' and h = h'

then;

⇒

Therefore, the ratio of the volume of the cone to the volume of the cylinder is, 1 : 3