Help me plz and thanks

Given a: b and b: c, find a: b: c. write the ratio in simplest form. a: b=6: 10 and b: c=21: 33

Cody was 165cm tall on the first day of school this year, which was 10% taller than he was on the first day of school last year.

Find the distance between (7,-6) and (-3,-9)