There are 7 red marbles + 4 blue marbles = 11 marbles.
The probability of choosing a red marble is
7 out of 11
"Out of" means "over", so that's
7 over 11 which is 
That would be the answer but the instructions say
giving your answer to 2 decimal places
So we change to a decimal:
We divide the bottom number 11 into 7, but instead of
7 we write it as 7.000, one more decimal place than 2
.636
11)7.000
6 6
40
33
70
66
4
Since the third decimal digit is 6,
and 6 is "5 or more", we round the
second decimal place 3 up to 4, and
eliminate the third decimal digit 6:
Answer = .64
We like to put a 0 in front, so it
would be better to write the answer
as 0.64
The big 0 is to "protect" the tiny decimal point. :)
Answer = 0.64
Edwin
