Jennie can make 7 quilts with 21 yards of material how many yards of material would be required to make 12 quilts ?

Can someone me out here and the tell me the greatest common factor

It is saturday morning and jeremy has discovered he has a leak coming from the water heater in his attic. since plumbers charge extra to come out on the weekends, jeremy is planning to use buckets to catch the dripping water. he places a bucket under the drip and steps outside to walk the dog. in half an hour the bucket is 1/5 of the way full. what is the rate at which the water is leaking per hour?

The owner of the plant nursery where you were tells you to fill 350 ml bottles from a 30 l from a fertilizer