One cookie and two brownies cost the same as two cookies and one brownie. One cookie and one brownie together cost $1. What is the cost, in cents, of one cookie?

50 cents

Step-by-step explanation:

Let's set up a system of equations. Let x be a cookie and y be a brownie then...

x+2y=2x+y

x+y=1

We can solve this using substitution

x=1-y

1-y+2y=2(1-y)+y

1+y=2-2y+y

1+y=2-y

-1=-2y

y=1/2

One brownie costs 50 cents and one cookie costs...

x+1/2=1

x=1/2

One cookie costs 50 cents

10 b/c 5*2 =10

step-by-step explanation: