# probability questions

#### susumandrai

##### New member
Please tell me if the answers to the following questions are correct.

Problem:
The following types of chocolate are in a box:
 Type of Chocolate Total Type of Centre Dark Milk White Soft 12 10 17 39 Hard 18 8 6 32 Total 30 18 23 71

If a chocolate is selected at random, calculate the following probabilities:
a) P(white chocolate)
b) P(soft centre)
c) P(dark chocolate with hard centre)
d) P(soft centre but not dark chocolate)
e) If the chocolate is white, find P(hard centre)
f) If the centre is soft, find P(chocolate is milk)

a) 23/71
b) 39/71
c) 18/71
d) 27/71
e) 6/23
f) 10/39

#### tkhunny

##### Moderator
Staff member
Why do you doubt? Which one did you do incorrectly on purpose? They are fine. Now go with confidence to the next section.

#### susumandrai

##### New member
Why do you doubt? Which one did you do incorrectly on purpose? They are fine. Now go with confidence to the next section.
I was worried about these two:
e) If the chocolate is white, find P(hard centre)
My worry - If the chocolate is white means that my sample space is only the soft white and hard white, that is the reason why the answer is 6/23
f) If the centre is soft, find P(chocolate is milk)
My worry - If the centre is soft means my sample space is Dark, Milk, and White Chocolates of soft centre only. This is the reason why the answer is 10/39

#### tkhunny

##### Moderator
Staff member
Read the definition of "Conditional Probability" two or three more times and raise that confidence level!