Answer:
3.
Step-by-step explanation:
3(n + 4) = 21
3n + 12 = 21
3n = 21 - 12 = 9
n = 3.
Answer: 
Step by step:

(Used a table of common angles)
Part A.
Ashwin had a 4-cm cube.
volume of cube = side^3
volume = (4 cm)^3 = 64 cm^3
Ashwin has 64 small cubes.
We need to find the volumes of all prisms in Part A. Only prisms with at most 64 cm^3 volume can be the answer.
A. v = 2 * 4 * 7 = 28
B. v = 4 * 5 * 6 = 120
C. v = 5 * 5 * 4 = 100
D. v = 4 * 7 * 5 = 140
E. v = 3 * 5 * 4 = 60
Part A. answer: A, E
Part B.
Dora had a 5-cm cube.
volume of cube = side^3
volume = (5 cm)^3 = 125 cm^3
Dora has 125 small cubes.
We need to find the volumes of all prisms in Part B. Only prisms with at most 125 cm^3 volume can be the answer.
A. v = 3 * 3 * 8 = 72
B. v = 3 * 4 * 5 = 60
C. v = 6 * 6 * 4 = 144
D. v = 5 * 8 * 4 = 160
E. v = 3 * 5 * 4 = 60
Part B. answer: A, B, E
Answer:
21, 17, 13
Step-by-step explanation:
Find the mean of the 2 given values
mean =
=
= 17
Noe find the mean of 25 and 17 and 17 and 9
mean =
=
= 21 and
mean =
=
= 13
Thus the 3 means are 21, 17 and 13, that is
25, 21, 17, 13, 9