Answer:
Step-by-step explanation:
Given that,
The radius of a cylinder, r = 5 cm
Height of the cylinder, h = 5 cm
We need to find the lateral surface area of the cylinder. The formula for the lateral surface area of the cylinder is given by :
Put all the values,
So, the lateral surface area of the cylinder is .
Let D be Daniel's present age, then we can represent Kevin's present age as 3D because Kevin is 3 times as old as Daniel.
We can write an expression for Daniel's age 4 years ago as D-4 and Kevin's age 4 years ago as 3D-4.
We are told that 4 years ago Kevin was 5 times as old as Daniel. We can write this information as:
Now let us solve our equation to find Daniel's present age.
Daniel's present age is 8 years. Now we will multiply 8 by 3 to get Kevin's present age as Kevin is 3 times old as Daniel.
Therefore, Kevin is 24 years old now.