Zachary and his children went into a bakery and he bought $15 worth of cupcakes and brownies. each cupcake costs $3 and each brownie costs $1.50. he bought 3 times as many brownies as cupcakes. determine the number of cupcakes and the number of brownies that zachary bought.

6 brownies and 2 cupcakes.

Step-by-step explanation:

Let the number of brownies be b and the number of cupckes be c.

We have the following system:

b = 3c

1.5b + 3c = 15

Substituting for  b in the second equation:

4.5c  + 3c = 15

7.5c = 15

c =  2.

Thus b = 3c = 6.

the radius is 2 times the diameter.

step-by-step explanation: