Answer:
28 cupcakes
24 brownies
56 cookies
Step-by-step explanation:
Since the question did not tell us what to look for, we can as well look for the amount of each treat used
Let x be the amount of cupcakes
Let y be the amount of brownies
Let z be the amount of cookies
If Mari had 4 more cupcakes than brownies, then;
x = y+4
y = x-4.....1
Also if she had twice as many cookies as cupcakes
z = 2x..... 2
If she had 108treats in total, then;
x + y+z = 108 ..... 3
Substitute 1 and 2 into 3;
x + (x-4)+2x = 108
2x+2x-4 = 108
4x-4 = 108
4x =108+4
4x =112
x = 112/4
x = 28
Hence she has 28cupcakes
Get y
From 1: y = x-4
y = 28-4
y = 24
Hence she had 24 brownies
From 2: z = 2x
z = 2(28)
z = 56
She had 56 cookies
