ratio prob help:-(????

Tweet

Hi! Mr.Expert, Can you please help me how to solve step by step, pls... 1)In a bag of red & blue marbles, the ratio of red to blue marbles is 7:8.Find the number of red marbles if the bag has a)48 blue marbles b)600 marbles. 2)It takes 2 workers 15 days to build a room.How many days does it takes 5 workers to build the same room? 3)1full bottle of water can water 3 plants for 2 days.How many days will 2 full big bottles water 2 plants? Many txs in advance, my kind friends:-)