Help!

Isabella's rain gauge showed 3 4/5 cm last Tuesday. This Tuesday, the rain gauge showed 5 7/10 cm. How many more cm of rain fell during the week?

A. 9 1/2 cm
B. 8 1/2 cm
C. 2 4/5 cm
D. 1 9/10 cm


And :

You are adding 6 3/4 + 3 2/3 using fraction strips. Explain how you rename the fraction part of the sum. ​