Give evidence and proof no links 1/What is the correct written expression for the variable expression: (3 - x)/7 *

the difference of 3 and x divided by 7
3 divided by the difference of 7 and x
the sum of 3 and x divided by 7
the difference of 3 divided by 7 and x

2.Johnny is 5 less than 3 times the age of Elizabeth. If Elizabeth is e years old, which expression shows Johnny's age? *

3e - 5
3e + 5
5 - 3e
5 + 3e

3.What is the value of 4a - 7b - 8, when a = 7 and b = 3? *

1
15
-1
-45

4.Jose has g video games. Tony has 8 fewer games than Jose. What variable expressions represents the total number of video games Jose and Tony have? *

g + 8
2g + 8
g - 8
g + (g - 8)

5. Which written expression represents the variable expression 1/2 (8 - y) *

One half of eight less than a number y
A number y less than half of eight
One half the difference between eight and a number y
the difference of one half of eight and a number y

Aprisoner is trapped in a cell containing three doors. the first door leads to a tunnel that returns him to his cell after two days of travel. the second leads to a tunnel that returns him to his cell after three days of travel. the third door leads immediately to freedom. (a) assuming that the prisoner will always select doors 1, 2 and 3 with probabili- ties 0.5,0.3,0.2 (respectively), what is the expected number of days until he reaches freedom? (b) assuming that the prisoner is always equally likely to choose among those doors that he has not used, what is the expected number of days until he reaches freedom? (in this version, if the prisoner initially tries door 1, for example, then when he returns to the cell, he will now select only from doors 2 and 3.) (c) for parts (a) and (b), find the variance of the number of days until the prisoner reaches freedom. hint for part (b): define ni to be the number of additional days the prisoner spends after initially choosing door i and returning to his cell.