The class starts out with 26 students, of whom 12 are girls and, perhaps unlike Mr Morris, are sure of it.
The probability of the first random choice being a girl is 12/26. If successful, there are now 25 students left, of whom 11 are girls. The probability of a girl on the 2nd random choice is 11/25. The probability that BOTH random choices are successful is (12/26) x (11/25). That's (132/650), or about 20.31% (rounded).
No. You can actually solve this question without doing any math. Her only score that is above a 90 is 93, so it will be brought down lower than a 90 very easily by the 77 and the 82.
Answer:
<u><em>x = 37/45</em></u>
Step-by-step explanation:
Here's how similar triangles work. We set up an equation as SIDE 1A/ SIDE 1B = SIDE 2A/ SIDE 2B
Ok, so these 2 triangles are similar, so we can set up a butterfly equation:
Side 1a would be 8x
Side 1b would be 5x +3
Side 2a would be 10x - 2
Side 2b would be 7x
----------------------------------------------------
Our equation would be
8x/(5x+3) = (10x-2)/7x
We cross multiply to get 8x(10x-2) = 7x(5x+3)
Instead of solving and getting squares, we can x on both sides and we get:
8(10x - 2) = 7(5x+3) ----> we simplify to get
80x - 16 = 35x + 21 ----> it's easy sailing from here.
45x = 37
<u><em>x = 37/45</em></u>
<u><em>gosh i hope it's right...</em></u>
