Question

In order to ensure the safety of school classrooms the local Fire Marshall does an inspection at Thomas Jefferson High School every month, looking for faulty wiring, overloaded circuits, etc. At TJHS the new Academic Wing has 5 math rooms, 10 science rooms, and 10 English rooms. The science rooms are divided into 8 biology and 2 chemistry rooms. Each month, the Fire Marshall randomly picks one of the rooms in the new wing to inspect each month. Define the following events:
S = the event the selected room is a science room
B = the event the selected room is a biology room
M = the event the s

Answer 1

In order to ensure the safety of school classrooms the local Fire Marshall does an inspection at Thomas Jefferson High School every month, looking for faulty wiring, overloaded circuits, etc. At TJHS the new Academic Wing has 5 math rooms, 10 science rooms, and 10 English rooms. The science rooms are divided into 8 biology and 2 chemistry rooms. Each month, the Fire Marshall randomly picks one of the rooms in the new wing to inspect each month. Define the following events:
S = the event the selected room is a science room
B = the event the selected room is a biology room
M = the event the selected room is a math room
E = the event the selected room is an English room
C = the event the selected room is a chemistry room
Calculate the probabilities of the events described below:
a) P(S) b) P(M or E) c) P(E or B) d) P(S and not C)

Answer 2

@ganeshie8

Answer 3

5 M
10 S (8 B, 2 C)
10 E

Answer 4

So, in total there are 25 rooms, eh ?

Answer 5

out of which 10 rooms belong to Science,

a) P(S) = 10/25 = 2/5

Answer 6

see if u can work part b

Answer 7

for b would it be P(M or E)= (5*10)/25= 2

Answer 8

Nope, u need to add

Answer 9

number of math or english rooms = 5+10 = 15
total number of rooms = 25

so, P(M or E) = 15/25 = 3/5

Answer 10

Ok so C) English or biology room will be = 10+8= 18
divided by the total number of room so it will be 18/25
so P(E or B) = 18/25=.75
is that correct?

Answer 11

thats \(\large \color{red}{\checkmark}\)

Answer 12

u made a minor calculation mistake

Answer 13

corrected below :

P(E or B) = 18/25=.72

Answer 14

okay ?

Answer 15

oh yeah i just look at the calculator wrong

Answer 16

but i got .72

Answer 17

0.72 is right

Answer 18

Ok . For C) how would i got about it?

Answer 19

u want to pick a Science room, but dont want it to be Chemistry

Answer 20

that means, u want to pick Biology room right ?

Answer 21

so, simply calculate probability for B

Answer 22

P(B) = ?

Answer 23

so P(B)= .32

Answer 24

Correct !

Answer 25

Awesome thank you so much for the help and walking me through it

Answer 26

np.. u wlc :)