Answer:
EF = 20 cm
Step-by-step explanation:
Here, we want to find the length of EF
To do this, we use the principle of similar triangles
The similar triangles we are considering here will be ;
FEA and FBD
when two triangles are similar, the ratio of their corresponding sides are equal
Let us calculate DC first
we can use Pythagoras’ theorem here and it is that the square of the hypotenuse equals the sum of the square of the two other sides
Using the triangle EDC
15^2 = 12^2 + DC^2
DC^2 = 225-144
DC^2 = 81
DC = 9
So the entire length of BD is 9 + 12 = 21 cm
Thus, we have it that;
Let EF be x
so DF = 15 + x
Hence;
BD/DF = AE/EF
21/15+x = 12/x
21x = 12(15 + x)
21x = 180 + 12x
21x-12x = 180
9x = 180
x = 180/9
x = 20 cm
EF = 20 cm
1) first pick red 5/9 blue 4/9
2) second pick when red has been picked red now becomes 4/8, blue stays 4/8
2) Second pick when blue has been picked blue now becomes 3/8, red stays 5/8
Mind you, you only need both different colours so:
first pick red 5/9 x sec pick blue 4/8 = 20/72
and first pick blue 4/9 x sec pick red 5/8 = 20/72
add both up 20/72 + 20/72 = 40/72 = 5/9
Twelve, two hundred and fourty five
Answer:
bd=cc=oc2
Step-by-step explanation:
