Answer:
4.24 hours
Step-by-step explanation:
Irina can paint 1/9 of a room in 1 hour since she can paint a room in 9 hours. 1/9x, where x is the number of hours she works and 1/9 of a room per hour is her speed, would be her part of the calculation.
Paulo can paint 1/8 of a room in 1 hour since he can paint an entire room in 8 hours. 1/8x, where x is the number of hours he works and 1/8 of a room per hour is his speed, would be his part of the equation.
1/9x + 1/8x = 1 (Irina's portion of the room plus Paulo's portion of the room equals one complete room) would be the equation.
Look for a denominator that has the same value as the numerator. Both 9 and 8 split evenly into 72 as the initial number. We multiply the top of 1/9 by 8 to convert the fraction and get 8/72x because 9*8 = 72. We multiply the top of 1/8 by 9 to convert the fraction and get 9/72x because 8*9 = 72. We have 8/72x+9/72x=1 currently.
17/72x=1
÷ both sides by 17/72:
17/72x ÷ 17/72 = 1÷17/72
∴ x=1/1 * 72/17
∴ x=72/17= 4.24
The irrational numbers are √10,√27,√99.
Answer: Choice A
The volume expression is 4/3 times pi times (3x)^3
===================================================
The volume of a sphere is found through the formula
V = (4/3)*pi*r^3
so we start with the fraction 4/3, multiply it with pi, and then multiply it with r^3
In this case, the radius is r = 3x because this is half of the diameter d = 6x
We simply replace the r with 3x in that formula above
V = (4/3)*pi*r^3
V = (4/3)*pi*( r )^3
V = (4/3)*pi*(3x)^3 ... replace r with 3x
Answer:
Surface area of the wood to be painted = (
+ r 
)
- 16
Step-by-step explanation:
Surface area of a cone is given as the sum of the surface area and the area of its base.
i.e Surface area = + Lr
where: L is the length of its slant height and r is the radius.
Applying the Pythagoras theorem,
L =
Thus,
Surface area = r (r + )
The given cylindrical hole has a radius of 4 cm and depth 2 cm.
The area of one of its circular surfaces =
= × 
= 16 
The surface area of the piece of wood to be painted = surface area of cone - area of cylindrical circular surface.
Surface area of the wood to be painted = r (r + ) - 16
Answer:
0.99+10=10.99
Step-by-step explanation:
