Problem Solving

Jerry has 3 flavors of ice cream in his parlor. How many options are there for George to pick a one-flavor, two-flavor or three-flavor order?

A. 2
B. 3
C. 4
D. 7
E. 8

The OA is D .

What are the formulas needed to solve this PS question? Experts, I would appreciate your help.

Since the order will not make any difference here, it is a combination question

He can choose 1 flavour in 3C1 ways = 3
2 flavors in 3C2 ways = 3
There is only one way of choosing 3 flavours = 1

Total no of ways = 3+3+1 = 7

Vincen wrote:Jerry has 3 flavors of ice cream in his parlor. How many options are there for George to pick a one-flavor, two-flavor or three-flavor order?

A. 2
B. 3
C. 4
D. 7
E. 8

Alternate approach 1:

Number of options for the first flavor = 2. (Chosen or not chosen).
Number of options for the second flavor = 2. (Chosen or not chosen).
Number of options for the third flavor = 2. (Chosen or not chosen).
To combine these options, we multiply:
2*2*2 = 8
Of these 8 options, one is not viable: if all 3 flavors are NOT chosen.
Subtracting the one inviable option from the total, we get:
8-1 = 7

The correct answer is D.

Alternate approach 2:

Since the answer choices are small, we can quickly list all of the possible options.
Let the 3 flavors be A, B and C.
Ways to choose 1 or more flavors:
A
B
C
AB
AC
BC
ABC
Total ways = 7