Problem Solving

LulaBrazilia wrote:If a number between 0 and 1/2 is selected at random, which of the following will the number most likely be between?

A) 0 and 3/20
B) 3/20 and 1/5
C) 1/5 and 1/4
D) 1/4 and 3/10
E) 3/10 and 1/2

We need to determine the LENGTH OF EACH INTERVAL.
The interval that has the greatest length, will be the most likely interval.

To determine the length of each interval, it may be faster to first convert the fractions to decimals. We get:

A) 0 and 0.15 (interval length = 0.15)
B) 0.15 and 0.2 (interval length = 0.05)
C) 0.2 and 0.25 (interval length = 0.05)
D) 0.25 and 0.3 (interval length = 0.05)
E) 0.3 and 0.5 (interval length = 0.2)

Answer: E

Cheers,
Brent

LulaBrazilia wrote:If a number between 0 and 1/2 is selected at random, which of the following will the number most likely be between?

A) 0 and 3/20
B) 3/20 and 1/5
C) 1/5 and 1/4
D) 1/4 and 3/10
E) 3/10 and 1/2

Alternatively, we might rewrite each fraction with a common denominator of 20 to get:

A) 0 and 3/20 (interval length = 3/20)
B) 3/20 and 4/20 (interval length = 1/20)
C) 4/20 and 5/20 (interval length = 1/20)
D) 5/20 and 6/20 (interval length = 1/20)
E) 6/20 and 10/20 (interval length = 4/20)

Answer: E

Cheers,
Brent