Wow! I never had problems this hard in middle school!
But you can do it!
First, we need to figure the number of flips Sara can do based on Jenny's.
Jenny = 120 and Sara - 120 x 3/8 (because she is only 3/8 of Sara's)
Calculate 120 x 3/8 = 45 flips
Now we know that Sara increased her amount of flips by 3 (45 +3 = 48)
And we know that Jenny decreased hers by 12 (120 - 12 = 108)
So now we have a ratio of 48:108, but we need to simplify that with factoring.
I am going to divide first by 2.
24:54
Then 2 again...
12:27
How about 3?
4:9
I think that is as far as we can go.
Sara is now doing 4 out of every 9 that Jenny does.
Check it!
108 (Jenny) x 4/9 = 48 (Sara) Yes! It checks.