The result of tossing a fair die 120 times is summarized below. Find the value of x
Number
1
2
3
4
5
6
Frequency
12
20
x
21
x - 1
28
A
19
B
20
C
21
D
22
Verified Correct Answer: B.
Step-by-Step Mathematical Solution
12 + 20 + x + 21 + x-1 +28 = 120
2x + 80 = 120
2x = 120 - 80
2x = 40
x = 20
Source: Myschool Past Questions Archive (Record #7847)