For this case, they ask us to determine which of the improper fractions (Numerator is greater than or equal to the denominator) given is not equivalent to "3".
Option A:
![\frac {21} {7} = 3](https://img.qammunity.org/2020/formulas/mathematics/middle-school/90t0nvmv024s0phjaavs1fhohou0ifmhyj.png)
Three times the number "7" gives "21".
Option B:
![\frac {21} {9} = \frac {7} {3}](https://img.qammunity.org/2020/formulas/mathematics/middle-school/v1q32qhqwresh1dyheu8l9kj03xe3793aj.png)
Note that if we divide the numerator and denominator by "3" we get the fraction \ frac {7} {3} other than the integer "3".
Option C:
![\frac {3} {1} = 3](https://img.qammunity.org/2020/formulas/mathematics/middle-school/mwfyf92hoawpfi9zh8w0u8mul6awqbh0cm.png)
Option D:
![\frac {27} {9} = 3](https://img.qammunity.org/2020/formulas/mathematics/middle-school/n6amwbpxbmijwqnkx1onfhq5a5eh3mvrkr.png)
Three times the number "9" gives "27"
Thus, the fraction that is not equivalent to "3" is:
![\frac {21} {9}](https://img.qammunity.org/2020/formulas/mathematics/middle-school/z5l5rbo31ahu9s0k5vvc4lihjat2dcvzd6.png)
Answer:
Option B