Answer:
495 combinations of 4 students can be selected.
Step-by-step explanation:
The order of the students in the sample is not important. So we use the combinations formula to solve this question.
Combinations formula:
is the number of different combinations of x objects from a set of n elements, given by the following formula.
How many combination of random samples of 4 students can be selected?
4 from a set of 12. So
495 combinations of 4 students can be selected.
Let the three numbers be x, y and z respectively, then
x + y + z = 62 . . . (1)
y = x - 4 . . . (2)
z = 4x . . . (3)
The above three expressions could be used to represent the numbers.
Solving the three equations, putting (2) and (3) into (1) gives
x + x - 4 + 4x = 62
6x - 4 = 62
6x = 62 + 4 = 66
x = 66/6 = 11
x = 11.
y = 11 - 4 = 7
z = 4(11) = 44
x = 11, y = 7, z = 44.
Answer: 60°
Step-by-step explanation: 180 - 120 = 60.
To find the volume of a cylinder, the equation used is V = 3.14r^2h
r = 4, and h = 3, so we input both numbers to get V = 3.14*4^2*3
V = 3.14*4^2*3 = 3.14*16*3 = 3.14*48=150.72
V = 150.7 ft^3
