Explanation

Total students = 27

Since 7 more girls than boys, let's represent the number of boys as x.

Number of girls = x + 7

Total students = Boys + Girls

27 = x + (x + 7)

Combine like terms:

27 = 2x + 7

Subtract 7:

20 = 2x

Divide by 2:

10 = x

Number of boys = 10

Number of girls = 10 + 7 = 17

Therefore:

Total girls in the class = 17

Last verified on 06-03-2026

Explanation

Student solved 20 questions in 20 minutes, so his speed is 1 question per minute.

He had 40 minutes to solve the test, but left 10 minutes early, so he worked for 40 - 10 = 30 minutes total.

Questions solved = 20 (in first 20 minutes) + 10 (in next 10 minutes) = 30 questions.

Last verified on 06-03-2026

Explanation

Given:

Price of 3 dozen eggs = 288

Step 1: Find total eggs in 3 dozen

1 dozen = 12 eggs
3 dozen = 3 × 12 = 36 eggs

So, 36 eggs cost 288

Step 2: Find the price of 1 egg

Price of 1 egg= 288/36​ =8

So, 1 egg costs 8

Step 3: Find how many eggs can be bought in 360

Number of eggs=360/8​=45

$$Question\; updated\; 03-March-2026$$

Explanation

Given:

- Average age of 5 members = 21  

  → Total age of 5 members = 21 × 5 = 105

- When grandfather is included (6 members), average becomes 21 + 9 = 30  

  → Total age of 6 members = 30 × 6 = 180

Now, Grandfather's age = 180 – 105 = 75 years

Explanation

First 4 even numbers: 2, 4, 6, 8

Sum = 2 + 4 + 6 + 8 = 20

Average = 20/4 = 5

Last verified on 15-02-2026

Explanation

Mean =  numbers of multiples/ sum of multiples of first five of 3

The average of the first five multiples of 3

= 3 + 6 +9 + 12 + 15 / 5

= 45/ 5

= 9

Last verified on 15-02-2026

Explanation

The sum of the first 10 natural numbers is:

1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10 = 55

Average = 55/10 = 5.5

OR

Formula for natural number= n(n+1)/2

n=10

Now

10(10+1)/2

10(11)/2

5(11)

55

Last verified on 15-02-2026

Explanation

Total marks = 87 + 85 + 92 + 78 + 68 = 410

Number of subjects = 5

Average = 410/5 = 82

Last verified on 07-02-2026

Explanation

Calculate Initial Age: The boy is 3 years old, and his sister is 3 times older.

This means she is  3 x 3 =9years old.

Find the Age Difference:

The constant age difference between them is 9-3 = 6 years.

Calculate Future Age: When the boy reaches 11 years old, the sister will still be 6 years older than him.

Final Result:  11 + 6 = 17

Explanation

1. Average of 6 numbers = 12

$$\text{Total of 6 numbers}=6\times 12=72$$

2. Add the new number 20:

$$\text{New total}=72+20=92$$

3. Total numbers now = 6 + 1 = 7

4. New average = Total ÷ Number of values

$$\text{New average}=92÷7\approx 13.14$$