We are given that there are a total of 78 students. If we set the following variables:

Then, the sum of all of these must be 78, that is:

Since there are 15 in chemistry and physics and 47 in chemistry, we may replace that into the equation and we get:

Simplifying:

Now we solve for P by subtracting 62 on both sides:

Therefore, there are 16 students in physics
Answer:
131
Step-by-step explanation:
x=6(25)-19
x=150-19
x=131
Answer:
Girls to boys = 1:2
Girls to students = 1:3
Boys to students = 2:3
Step-by-step explanation:
So, let's subtract the number of girls from the number of students in the class:
60 - 20 = 40
This means that for every 20 girls there are 40 boys in the ratio of girls to boys:
20:40
This can be simplified down by factoring, here we can divide by 20:
(20 ÷ 20) : (40 ÷ 20)
1:2
So the ratio of girls to boys is 1:2
The ratio of boys to students can be calculated via:
40:60
This can be simplified by dividing by 20 again:
(40 ÷ 20) : (60 ÷ 20)
2:3
So the ratio of boys to students is 2:3
The ratio of girls to students can be put in a ratio of:
20 : 60
This can be simplified down by dividing by 20:
(20 ÷ 20) : (60 ÷ 20)
1:3
So the ratio of girls to students is 1:3
Hope this helps!
1. Total number of marbles=10 red marbles+80 green marbles+110 orange marbles=200 marbles
2. Let's call "V" the event that consists that he selects a green marble from the bag. Then:
P(x)=80/200
P(x)=0.4
3. This problem can be represented by a binomial distribution, where:
P=0.4
q=1-P=0.6
n=50
4. The expect value in a binomial function is written as below:
E(x)=nxP
E(x)=50x0.4
E(x)=20
The answer is: He can expect 20 zucchini.