(a) there are 8C2 = 28 ways of picking 2 girls from 8
And there are 21C4 = 5985 ways of picking 4 boys
Required number of ways for 2g / 4b = 28 * 5985 = 167,580
(b) at least 2 girls means combinations of 2g/4b , 3g,3b , 4g/2b , 5g 1b or
6 girls.
2g/4b = 167,580 ways
3g/3b = 8C3 * 21C3 = 56 * 1330 = 74,480
4g/2b = 8C4* 21C2 = 70 * 210 = 14,700
5g 1b = 8C5* 21 = 56*21 = 1176
6 girls = 8C6 = 28
adding these up we get the answer to (b) which is 257,964
Answer:
42 minutes
Step-by-step explanation:
Here we want to calculate the number of minutes ran in total.
Kindly note that;
Time = distance/speed
Her starting speed is 10 miles/hour
but she ran for 12 minutes.
Kindly note that 12 minutes = 12/60 = 1/5 = 0.2 hour
So total distance in the first 12 minutes is speed * time = 10 * 0.2 = 2 miles
Now the rest of distance to run would be ;
5 -2 = 3 miles
She ran 3 miles at a speed of 6 miles per hour.
Time spent here is 3/6 = 0.5 hours which is same as 30 minutes
Total time spent = 30 + 12 = 42 minutes
Answer:
Step-by-step explanation:
the value of the cookies can be 1.20
Answer: The answer is 30%.
Step-by-step explanation: Given that there is a group of 10 light users and 10 heavy users. We are to find the probability that exactly 3 of the 20 users are HIV positive.
We have the following four possible cases -
(i) All 3 are light users.
(ii) 1 is a light user and 2 are heavy users.
(iii) 2 are light users and 1 is a heavy user.
(iv) All 3 are heavy user.
Since there is a 45% chance of a light user to be HIV positive and 55% chance of a heavy user to be HIV positive, so the required probability is given by
Thus, the probability is 30.
