Answer:
B 120 different combinations
Step-by-step explanation:
There are 6 letters to choose from
Picking a letter for the first spot 6
Then there are 5 letters left
Picking a letter for the second spot 5
Then there are 4 letters left
Picking a letter for the second spot 4
6*5*4
= 120
We have 55% and 80% antifreeze. We need 90 gallons of 75%.
F - 55% and E - 80%
A) F + E = 90
B) .55 F + .80 E = 67.50 (which is .75 * 90) Multiplying A) by -.55
A) -.55 F -.55 E = -49.50 (which is -.55 * 90) then adding A) & B)
.25 E = 18
E = 72 gallons of 80% and
F = 18 gallons of 55%
********* DOUBLE CHECK ******************
72 * .80 = 57.60 and 18 * .55 = 9.90
57.60 + 9.90 = 67.50 gallons of antifreeze and we have 90 total gallons
(67.50 / 90) * 100 = 75% correct!
Source: 1728.com/mixture.htm
Answer:
12(5x-y)
Step-by-step explanation:hope this help
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