Math help please

Question

On Saturdays during the summer, Tara's Food Truck tends to sell a ratio of 3 water bottles to 7 cans of pop. Tara needs to restock her supplies, if she buys 90 bottles of water, how many cans of pop should she buy? (Water bottles: pop)

Answer 1

7/3=pop/90, pop=90×7/3=30×7=210 cans of pop