Answer:
Surface Area is 56π cm²
Step-by-step explanation:
The area for a cylinder's surface area is
a=2πrh+2πr²
The cylinder base's radius is 4 cm
The cylinder's height is 3 cm
Putting into the equation:
a=2×π×4×3+2×π×4²
a=2π×4×3+2×π×4²
a=8π×3+2×π×4²
a=24π+2×π×4²
a=24π+2×π×16
a=24π+2π×16
a=24π+32π
a=56π
The surface area of the cylinder is 56π cm².
Answer:
81.37
Step-by-step explanation:
100 - 18.63 = 81.37
Answer: 46 years
Step-by-step explanation:
Let the father's age be x and the son's age be y, then 3 years ago:
Father = x - 3
son = y - 3
Then , from the first statement :
x - 3 = 3 ( y - 3 )
x - 3 = 3y - 9
x = 3y - 9 + 3
x = 3y - 6 .......................................... equation 1
In five years time
father = x + 5
son = y + 5
Then , from the second statement
x + 5 = 2 ( y + 5 )
x + 5 = 2y + 10
x = 2y + 10 - 5
x = 2y + 5 ........................ equation 2
Equating equation 1 and 2 , we have
3y -6 = 2y + 5
add 6 to both sides
3y = 2y + 5 + 6
subtract 2y from both sides
3y - 2y = 11
y = 11
substitute y = 11 into equation 1 to find the value of x
x = 3y - 6
x = 3(11) - 6
x = 33 - 6
x = 27
This means that the father is presently 27 years and the son is presently 11 years.
In four years time
father = 27 + 4 = 31
son = 11 + 4 = 15
sum of their ages in four years time will be
31 + 15 = 46 years
X and y
x=2y+9
x-y=22
*x is the larger number*
plug in x to solve for y
2y+9-y=22
y+9=22
-9 both sides
y=13
plug in y and solve for X
x=2 (13)+9
x=26+9
x=35
