A packet of sweets contains only yellow and purple sweets. The ratio of yellow to purple sweets in the packet is 2:1. If there are 9 sweets in total, how many purple sweets are there?

3 purple

Step-by-step explanation:

yellow: purple: total

2   :         1    :  2+1 =3

We have 9 total sweets so we need to multiply each number by 3

2*3  :  1*3    : 3*3

6  :      3      :  9

There are 6 yellow  3 purple and 9 total sweets

thus, the first answer choice, y = sec x, is the correct one