Let x be the number of red fish
3:5 = x:20
3/5 = x/20
(Cross method)
5x = 60
x =12
There are 12 red fish in the fish tank.
Answer:
<em>The probability that the second ball is red is 71%</em>
Step-by-step explanation:
<u>Probabilities</u>
We know there are 5 red balls and 2 green balls. Let's analyze what can happen when two balls are drawn in sequence (no reposition).
The first ball can be red (R) or green (G). The probability that it's red is computed by

The probability is's green is computed by

If we have drawn a red ball, there are only 4 of them out of 6 in the urn, so the probability to draw a second red ball is

If we have drawn a green ball, there are still 5 red balls out of 6 in the urn, so the probability to draw a red ball now is

The total probability of the second ball being red is

The probability that the second ball is red is 71%
Answer:
which agrees with option"B" of the possible answers listed
Step-by-step explanation:
Notice that in order to solve this problem (find angle JLF) , we need to find the value of the angle defined by JLG and subtract it from
, since they are supplementary angles. So we focus on such, and start by drawing the radii that connects the center of the circle (point "O") to points G and H, in order to observe the central angles that are given to us as
and
. (see attached image)
We put our efforts into solving the right angle triangle denoted with green borders.
Notice as well, that the triangle JOH that is formed with the two radii and the segment that joins point J to point G, is an isosceles triangle, and therefore the two angles opposite to these equal radius sides, must be equal. We see that angle JOH can be calculated by : 
Therefore, the two equal acute angles in the triangle JOH should add to:
resulting then in each small acute angle of measure
.
Now referring to the green sided right angle triangle we can find find angle JLG, using: 
Finally, the requested measure of angle JLF is obtained via: 
Answer:
x = 2 or
x = -7
Step-by-step explanation:
(x - 2)(x + 7) = 0
x - 2 = 0
Add 2 to both sides
x - 2 + 2 = 2 + 0
x = 2
OR
x + 7 = 0
Subtract 7 from both sides
x + 7 - 7 = 0-7
x = -7
Therefore
x = 2 or
x = -7