OCR S1 2010 June — Question 7

Exam BoardOCR
ModuleS1 (Statistics 1)
Year2010
SessionJune
TopicCombinations & Selection

7 The menu below shows all the dishes available at a certain restaurant.
Rice dishesMain dishesVegetable dishes
Boiled riceChickenMushrooms
Fried riceBeefCauliflower
Pilau riceLambSpinach
Keema riceMixed grillLentils
PrawnPotatoes
Vegetarian
A group of friends decide that they will share a total of 2 different rice dishes, 3 different main dishes and 4 different vegetable dishes from this menu. Given these restrictions,
  1. find the number of possible combinations of dishes that they can choose to share,
  2. assuming that all choices are equally likely, find the probability that they choose boiled rice. The friends decide to add a further restriction as follows. If they choose boiled rice, they will not choose potatoes.
  3. Find the number of possible combinations of dishes that they can now choose.