Answer:
Number of ml of 40% sugar = x = 1000mL
Number of ml of 85% sugar used = y = 800mL
Step-by-step explanation:
Let the
Number of ml of 40% sugar = x
Number of ml of 85% sugar used = y
From the above question, our system of equations is given as:
x + y = 1800mL ....... Equation 1
x = 1800 - y
40% × x + 85% × y = 60% × 1800mL
0.4x + 0.85y = 1080.... Equation 2
We substitute 1800 - y for x in Equation 2
0.4(1800 - y) + 0.85y = 1080
720 - 0.4y + 0.85y = 1080
- 0.4y + 0.85y = 1080 - 720
0.45y = 360
y = 360/0.45
y = 800mL
Solving for x
x = 1800 - y
x = 1800 - 800
x = 1000mL
Therefore,
Number of ml of 40% sugar = x = 1000mL
Number of ml of 85% sugar used = y = 800mL
. r is the radius and l is the slant height. In your case it would be 
.