Question

Anita's music collection consists of only rock, pop and jazz CDs. The ratio of the number of rock CDs to
the number of pop CDs is 3:4. The ratio of the number of rock CDs to the number of jazz CDs is 5:4.
If Anita has 20 pop CDs, what is the TOTAL number of CDs in her collection?
А
47
B
51
с
55
D
60

Answer 1

Given:

Anita's music collection consists of only rock, pop and jazz CDs. The ratio of the number of rock CDs to the number of pop CDs is 3:4. The ratio of the number of rock CDs to the number of jazz CDs is 5:4. Anita has 20 pop CDs

To find:

What is the TOTAL number of CDs in her collection?

Solution:

From the given information, we have the data as follows.

Anita has 20 pop CDs.

The ratio of the number of rock CDs to the number of pop CDs is 3:4.

R/P = 3/4

4R = 3P

R = 3/4 P

R = 3/4 × 20

R = 15

Therefore, Anita has a total of 15 rock CDs.

The ratio of the number of rock CDs to the number of jazz CDs is 5:4.

R/J = 5/4

4R = 5J

J = 4/5 R

J = 4/5 × 15

J = 12

Therefore, Anita has a total of 12 jazz CDs.

The total number of CDs are:

Pop + Rock + Jazz = 20 + 15 + 12 = 47

Therefore, the number of CDs Anita has are 47, thus, the option (A) is correct.