The names, or notes, of all the white keys on a piano are written on pieces of paper and placed in a cup. There are 7 sets of the notes d, e, f, and g and 8 sets of the notes a, b, and c. If a person draws one note out of the cup without looking , what are his or her chances of getting a c ?

Question

The names, or notes, of all the white keys on a piano are written on pieces of paper and placed in a cup. There are 7 sets of the notes d, e, f, and g and 8 sets of the notes a, b, and c. If a person draws one note out of the cup without looking , what are his or her chances of getting a c ?

Answer 1

(7 * 4) + (8 * 3) = total notes?

8/total notes

Answer 2

To determine the chances of getting a "c" note from the cup, we need to calculate the probability of drawing a "c" note compared to the total number of notes in the cup.

Total number of "c" notes: 8 sets
Total number of notes in the cup: 7 sets (d, e, f, g) + 8 sets (a, b, c) = 15 sets

So, the probability of drawing a "c" note is:

P(c) = Number of "c" notes / Total number of notes
= 8 sets / 15 sets

Simplifying this fraction, we get:

P(c) = 8/15

Therefore, the chances of getting a "c" note are 8/15 or approximately 0.5333 (rounded to four decimal places).

Answer 3

To find the probability of drawing a C note from the cup, we first need to determine the total number of white keys in the cup, as well as the number of C notes.

Given that there are 7 sets of the notes D, E, F, and G, we can calculate the number of these notes as follows:
Number of D, E, F, G notes = 7 sets * 4 notes per set = 28 notes

Similarly, there are 8 sets of the notes A, B, and C, so we can calculate the number of C notes as follows:
Number of C notes = 8 sets * 1 note per set = 8 notes

The total number of white keys in the cup is the sum of the D, E, F, G notes and the A, B, C notes:
Total number of white keys = Number of D, E, F, G notes + Number of A, B, C notes = 28 notes + 8 notes = 36 notes

Therefore, there are 36 notes in the cup, out of which 8 are C notes.

Now, to find the probability of getting a C note, we divide the number of desired outcomes (C notes) by the total number of possible outcomes (total notes in the cup):
Probability of getting a C note = Number of C notes / Total number of white keys = 8 notes / 36 notes

Simplifying the fraction, we get:
Probability of getting a C note = 2/9

So, the person's chances of drawing a C note from the cup without looking are 2/9 or approximately 0.22, which can also be expressed as 22%.