Answer:
48 cups
Step-by-step explanation:
Matthew and Mark were selling cups of lemonade.
Let the number of cups that Matthew sold = x
The number of cups Mark sold = y
Together they sold 81 cups.
= x + y = 81 cups...... Equation 1
Matthew sold 15 more cups of lemonade than Mark.
x = y + 15 cups
Substituting y + 15 for x in Equation 1
y + 15 + y = 81 cups
2y +15 = 81 cups
2y = 81 -15
2y = 66 cups
y = 66 cups/2
y = 33 cups
Hence, the number of cups Mark sold = 33 cups.
The number of cups Matthew sold is calculated as:
= x = y + 15 cups
x = 33 cups + 15 cups
x = 48 cups
