Question

Eight out of 21 instruments in the band are woodwinds. If there are 63 instruments in the band, how many more are not woodwinds?

Answer 1

39

Explanation:

If 8 out of 21 are WOODWINDS, we can say:

21 - 8 = 13

13 out of 21 ARE NOT woodwinds.

This is the ratio.

Now, there are 63 total instruments. We need to find how many ARE NOT woodwinds. We equate the ratio found (13 out of 21) with total 63 instruments and find "x" [let x be number of instruments that are NOT woodwinds].

Shown below:

`(13)/(21)=(x)/(63)\\21x=63*13\\21x=819\\x=(819)/(21)\\x=39`

Hence, out of 63 instruments, we can say that 39 are not woodwinds