Bill is making a sandwich. He may choose any combination of the following: lettuce, tomato, carrot, cheese, cucumber, beetroot, onion, ham. Find the probability that:
a the sandwich contains ham
b the sandwich contains three ingredients
c the sandwich contains at least three ingredients.

Question

RRRRRIIIIIII · Answer

I got a) 1/8 b)56 c) don't know
the answers are a) 2^7/2^8-1 b)56/255 c)73/85

coolxspree · Answer

how many options are there to choose from?

RRRRRIIIIIII · Answer

@coolxspree wrote:

how many options are there to choose from?

8

coolxspree · Answer

right

RRRRRIIIIIII · Answer

@coolxspree wrote:

how many options are there to choose from?

lettuce, tomato, carrot, cheese, cucumber, beetroot, onion and ham

coolxspree · Answer

ok so #1 is correct

coolxspree · Answer

or option a i mean

RRRRRIIIIIII · Answer

@coolxspree wrote:

ok so #1 is correct

#1 is wrong, the right one is the answer

coolxspree · Answer

wait huh?

RRRRRIIIIIII · Answer

@coolxspree wrote:

or option a i mean

I am so confused about #1's answer

RRRRRIIIIIII · Answer

@coolxspree wrote:

wait huh?

the answer is 2^7/2^8-1 but I got 1/8

coolxspree · Answer

where did u get 2^7/2^8-1 from?

RRRRRIIIIIII · Answer

@coolxspree wrote:

where did u get 2^7/2^8-1 from?

this is the answer in the textbook

coolxspree · Answer

oh