The sum of the first n natural numbers and 0=
n*(n+1)/2
32 40%
80 100
to find the answer, you do 32 times 100, the. divide that by 40 which equals 80
The surface area of a right cylinder is the sum of the areas of the lateral face and the circular bases. The lateral face is really just a rectangle with the same height as the cylinder and a length equal to the circumference of the circular base.
If the radius of the base is
and the height is
, then the surface area of the cylinder is
You're given that the area is
and the radius is
, so you have
Answer:
176 mm
Step-by-step explanation:
The circumference of a circle is the perimeter of a circle (length of a circle). The circumference of a circle is given as:
Circumference (C) = 2πr = πd, where d is the diameter
The circumference of a circle with diameter 7 mm is:
C = πd = 22/7(7) = 22 mm
The length of the paper to round the cylindrical pencil is the same as the perimeter of the pencil which is 22 mm.
To round the pencil 8 times, the length of the paper needed = 8 × 22 mm = 176 mm
Answer:
7 = 49 ÷ r
Step-by-step explanation:
To find the equation that is true when r = 7, we need to find a number after the equals sign that is a multiple of 7.
Multiples of 7:
7, 14, 21, 28, 35, 42, 49, 56, 63, 70, 77...
Therefore, the only answer option in which the number after the equals sign is a multiple of 7 is:
7 = 49 ÷ r
To prove this, input r = 7 into each of the equations:
6 = 30 ÷ r
⇒ 6 = 30 ÷ 7
⇒ 6 ≠ 4.285... ← incorrect!
7 = 54 ÷ r
⇒ 7 = 54 ÷ 7
⇒ 7 ≠ 7.714... ← incorrect!
7 = 49 ÷ r
⇒ 7 = 49 ÷ 7
⇒ 7 = 7 ← correct!
9 = 72 ÷ r
⇒ 9 = 72 ÷ 7
⇒ 9 ≠ 10.285... ← incorrect!
