Answer: Todd used 27 black tiles.
Step-by-step explanation:
Let x represent the number of black tiles that Todd used.
Todd uses 21 white tiles & some black tiles to make a mosaic. This means that the total number of white and black tiles that Todd used is 21 + x
Each tile has an area of 3 square centimeters. This means that the total area covered by the white tiles is
21 × 3 = 63 square centimeters
Also, the total area covered by the black tiles is
3 × x = 3x square centimeters
The mosaic has a total area of 144 square centimeters. This means that
3x + 63 = 144
3x = 144 - 63
3x = 81
x = 81/3 = 27
You would -a to get 6x=5-a then divide by 6 which you would get your final answer which is x=5-a/6
Answer:
The answer is C.
Step-by-step explanation:
Hit 'em with the Law of Sines.
sin(A)/a = sin(B)/b.
Let's say x is equal to "A", thus 5 is "a".
sin(x)/5 = sin(B)/b.
We could go for the obvious choice for "B", which would be the 90 degrees shown. To solve for the hypotenuse which will be "b", let's use the Pythagorean Theorem:
a^2 + b^2 = c^2
5^2 + 20^2 = c^2
25 + 400 = 425
sqrt(425) = about 20.6, which we can now substitute "b" with.
sin(x)/5 = sin(90)/20.6
sin(x)/5 = 1/20.6
sin(x)/5 = 0.04854...
sin(x) = 0.2427...
You can plug in sin^-1(0.2427) into your calculator, and you should end up with something like 14.047... which equates to answer choice C.
The probability that a girl will be selected from the class is 0.7
Answer:
1 8/9
Step-by-step explanation:
4 1/9 + 1 8/9=6 ........
