Calcualate 40% (0.40) times 20 to get that there are 8 boys in the class. The rest must be girls, so 20 - 8 gives you 12 girls. 25% (0.25) times the 8 boys gives you that 2 of the boys wear glasses. 50% (0.5) times the 12 girls tives you that 6 girls wear glasses. Add together the 2 boys and the 6 girls that wear glasses to get that a total of 8 students wear glasses.
Answer:
1.43%
Step-by-step explanation:
we have that we can solve it by means of binomial, in this case m = 25. Also the probability of head is 50%. we need to know when it falls 7 times, therefore x = 7
the formula is:
P (x) = mCx * p ^ x * q ^ (m-x)
we know that p is 0.5 therefore q is equal to 0.5, replacing:
P (7) = 25C7 * 0.5 ^ 7 * 0.5 ^ (25-7)
P (7) = 25! / (7! * (25-7)!) * 0.5 ^ 7 * 0.5 ^ (25-7)
P = 0.0143
that is, the probability is 1.43%
When you divide a fraction by a fraction, you're really just multiplying by a reciprocal. A reciprocal is the fraction flipped around.
So, 1/8 <span>÷ 1/4 is the same thing as 1/8 x 4/1
Now, you just multiply. 1 times 4 is 4. 8 times 1 is 8.
1/8 x 4/1=4/8
4/8 simplified is 1/2
So that is how 1/8</span><span>÷1/4=1/2</span>
Answer:
? = 109 degrees
Step-by-step explanation:
45 + 75 + _ = 180 ( look for vertical angles)
45 + 75 + 60 = 180
60 +79 + _ = 180 (look for a straight line that forms 180 degrees)
60 + 79 + 41 = 180
68 + 41 + _ = 180 (look for a triangle that adds up to 180)
68 + 41 + 71 =180
180 - 71 = 109 (look for a linear pair)
