If the area of a number

[BTGmoderatorDC]

If the area of a number is defined as the difference between that number's greatest and least prime factors, what is the area of 100 ?

A. 0
B. 2
C. 3
D. 5
E. 9

How to find the area?

OA C

[Brent@GMATPrepNow]

If the area of a number is defined as the difference between that number's greatest and least prime factors, what is the area of 100 ?

A. 0
B. 2
C. 3
D. 5
E. 9

This question begs us to find the prime factorization of 100
100 = (2)(2)(5)(5)
So, 5 is the GREATEST prime factor of 100
And 2 is the LEAST prime factor of 100

Area of a number = (the number's GREATEST prime factor) - (the number's LEAST prime factor)
Area of 100 = 5 - 2
= 3
Answer: C

Cheers,
Brent

[EconomistGMATTutor]

If the area of a number is defined as the difference between that number's greatest and least prime factors, what is the area of 100 ?

A. 0
B. 2
C. 3
D. 5
E. 9

How to find the area?

OA C

Hi lheiannie07,
Let's take a look at your question.

In the first step we will write as a product of its prime factors.
$$100=2\times2\times5\times5$$

Largest prime factor = 5
Smallest prime factor = 2

As defined in the question statement:
Area = Largest prime factor - smallest prime factor
$$Area=5-2=3$$

Therefore, Option C is correct.

Hope it helps.
I am available if you'd like any follow up.

[Scott@TargetTestPrep]

If the area of a number is defined as the difference between that number's greatest and least prime factors, what is the area of 100 ?

A. 0
B. 2
C. 3
D. 5
E. 9

How to find the area?

OA C

The greatest prime factor of 100 is 5, and the least is 2. Thus, the area of 100 is 5 - 2 = 3.

Answer: C