I need help i do not understand these questions

Aconstruction worker has rope 9 m long he needs to cut it in pieces that are each 3 /5 m long how many such pieces can he cut without having any rope leftover?

Which set of side lengths form a right side? a) 3ft,6ft,5ft b)50 in,48in,14in c)53m,48m,24m d)8cm,17cm,14cm

Astock has a 25% probability of increasing by $10 and a 75% probability of decreasing by $5. what is the stocks expected increase or decrease?