………………………………….. x z z z

a: 7:3

b:by reading 10 hours

a: 4 : 1

b: 12 (water) : 3 (sugar)

Step-by-step explanation:

ratio is similar to a fraction

water to sugar

the "to" is for what of every what it needs

to = can be used as ":"

For example:

For every 1 cup of sugar you need 4 cups of water to make the humming bird nectar. (it needs to be IN ORDER which is why for letter 'a' I did it water to sugar)

answer: for each 3 girls there is 2 boys . 3: 2

hope this ! (:   mark me as brainliest if you can