Question

Mei does 6 problems in 18 minutes. How many can she complete in 12 minutes

Answer 1

Do cross multiplication

  6  =  x
 18    12

Now cross multiply

(6)(12) = (18)(x)

       72 = 18x

Divide both sides by 18
     
    
     72  = 18x
     18      18

      4   = x

So tMei can complete 4 problems in 12 minutes.