Question

in class 10A,there are 30 boys and 20 girls.in 10B,there are 15 boys and 25 girls.one student is to be selected from each class.

a) what is the peobability of both being girls?
b) what is the probability of both being boys?
c) what is the probability of one boy and one girls?

Answer 1

Answer:

a)1/4

b)9/40

c)....

Step-by-step explanation:

(20/50)×(25/40)=1/4

(30/50)×(15/40)=9/40

for one boy & one girl,

((30/50)+(15/40))×((20/50)+

(25/40))= find your answer....

note__ for" or" we are adding and for "and" we are multiplying probabilities.

mark as brainliest plz. .. on top of my answer..

Answer 2

a) 0.125, b) 0.1124, c) 0.505

Step-by-step explanation:

Since we have given that

Number of boys in 10A = 30

Number of girls in 10A = 20

Number of boys in 10B = 15

Number of girls in 10B = 25

So, we need to select one student from each class.

So, a) what is the probability of both being girls?

$\dfrac{^{20}C_1\times ^{25}C_1}{^{90}C_2}\\\\=\dfrac{20\times 25}{4005}\\\\=0.125$

b) what is the probability of both being boys?

$\dfrac{^{30}C_1\times ^{15}C_1}{^{90}C_2}\\\\=\dfrac{30\times 15}{4005}\\\\=\dfrac{450}{4005}\\\\=0.1124$

c) what is the probability of one boy and one girls?

$\dfrac{^{45}C_1\times ^{45}}{^{90}C_2}\\\\=\dfrac{45\times 45}{4005}\\\\=\dfrac{2025}{4005}\\\\=0.505$

Hence, a) 0.125, b) 0.1124, c) 0.505.

# learn more:

In class 10A,there are 30 boys and 20 girls.in 10B,there are 15 boys and 25 girls.one student is to be selected from each class.

a) what is the peobability of both being girls?

b) what is the probability of both being boys?

c) what is the probability of one boy and one girls?

https://brainly.in/question/11737089