Explanation

Given:

mean=25

the sum of all observations= 350

To find:

number of observations

Solution:

The formula for mean

Mean = sum of all observations 

            number of observations

Putting all the values

25= 350/number of observations

number of observations= 350/25

∴ number of observations=  14

Explanation

Total students = 52

No. boys = 25

No. girls = 27

Total weight of boys = 42 X 25 = 1050

Total weight of 52 students = 52 X 40 = 2080

Total weight of girls = 2080 - 1050 = 1030

Average weight of girls = 1030 / 27 = 38.15 Kgs

sh25-8-2023

Explanation

8 hours of work, Ali earns Rs 120

1 hour of work, Ali earns Rs 15

22 hours of work, Ali earns Rs = 15 x 22 =330

Explanation

Given information:

1. The average of the first three numbers (A, B, C) is 15

   $$frac{A + B + C}{3} = 15$$ $$A + B + C = 45$$

2. The average of the last three numbers (B, C, D) is 16

   $$frac{B + C + D}{3} = 16$$ $$B + C + D = 48$$

3. The last number (D) is 19

   $$B + C + 19 = 48$$ $$B + C = 29$$

Finding A

We already have:

$$A + B + C = 45$$

Substituting $B + C = 29$:

$$A + 29 = 45$$$$A = 45 - 29$$ $$A = 16$$

Explanation

Explanation

Explanation

Let the number of girls and boys each be x, x=2(x-8) boys=x girls=x-8 =>x=2x-16 =>x=16 =>number of girls and boys together=16+16=32

Explanation

P(M)=pass in maths P(E)=pass in English P(E and M)= passing in both English and Maths Given P(E)=60%=0.6 P(E and M)=54%=0.54 M and E both events are independent then: P(E and M)=P(E)*P(M) P(M)=P(E and M)/P(E) P(M)=0.54/0.60=0.9 P(M!)= fail in maths P(M!)=1-p(M):(complement) P(M!)=1-0.9=0.1 P(M!)=10%

Explanation

Let sum = X. Then S.I = 16x/25

Let rate = R% and Time = R years.

Therefore,  (x * R * R)/100 = 16x/25   =>  R = 40/5 = 8

Therefore, Rate = 8% and Time = 8 years.

Explanation

The number of men= 5/11 x 33 = 15,

so out of 33 teachers,

men are 15

and women are 18. 5:6 can be written as 15:18.

For making it 1:1, 15+3: 18,

so 3 male teachers would be hired