Question

One morning . The shirt shop sold 15 T-shirt. Of the T-shirts sold, 1/5 were gray. The rest were white. How many white T-shirts were sold?

Answer 1

If 15 t-shirts were sold and 1/5 were grey,
     
                    then  4/5 of the shirts were white 

Now,   4/5 of 15 = 12
   
                ∴ of the shirts sold, 12 were white