30 : 48 as a ratio in simplest form

Samantha swam upstream for some distance in one hour. she then swam downstream the same river for the same distance in only 12 minutes. if the river flows at 4 mph, how fast can samantha swim in still water?

Which of the following statement about pascal's triangle are true?

What is the value of the expression 9+n/3-6 when n = 12? 1. 5. 7. 12.