Explanation

Finding the Remaining Students

Total Boys: 20

Total Girls: 30

Total Students: 20 + 30 = 50

Students taken for the tour: 73%

Remaining percentage: 100% − 73% = 27%

Remaining students: 27% of 50

= 50 × 27 ÷ 100

= 13.5

13.5 ≈ 14 students (approximately).

Explanation

20% of number = 40

To find the original number: Given value ÷ percentage × 100.

Number = 40 ÷ 20 × 100

Number = 200

Last updated: NA on 26-09-2026

Explanation

All students must take Math.

Jake is a student.

Therefore, Jake has to take the Math class.

Explanation

Given sequence: 4, 11, 7, 14, 10, 17, __, 20

Two alternating series are used:

First series: 4 → 7 → 10 → 13 (+3 each time)

Second series: 11 → 14 → 17 → 20 (+3 each time)

Missing number: 13

Explanation

A coin has 2 possible outcomes each time:

• Head (H)
• Tail (T)

If the coin is flipped 3 times, the total possible outcomes are:

2^3 = 8 

The possible outcomes are:

HHH, HHT, HTH, HTT, THH, THT, TTH, TTT

Only one outcome gives 3 heads: HHH.

Therefore:

Formula

P(3 heads)=Favourable outcomes​/Total outcome=1/8

1/8=0.125 or 12.5%

Explanation

Let the number be x.

3% of x = 60

3/100 x X = 60

X= 60 x 1000/3

$$x = frac{60 times 100}{3}$$ x=2000​

Explanation

Each group moves one letter forward, while the last letter skips one position:

Observe each position separately:

1st letters: A → B → C → D

2nd letters: B → C → D → E

3rd letters: C → D → E → F

4th letters: E → F → G → H

Therefore:

ABCE → BCDF → CDEG → DEFH

Explanation

Cost Price (CP) = Rs. 800
Selling Price (SP) = Rs. 1,000

Gain = SP − CP

$$=1000-800=200$$

Gain % = (Gain ÷ CP) × 100

$$=$$200/800​×100

=25%

Last updated by NA on 09-0-2026

Explanation

The speaker's mother has only one daughter.

That daughter is the speaker's sister.

The man's mother = speaker's sister.

Therefore, the woman is the man's sister.

Explanation

In the Tree of Rumour problem, one person passes the rumour to 2 other people every 5 minutes.

Therefore, the total number of people triples every 5 minutes.

0 minutes → 1 person

5 minutes → 3 persons

10 minutes → 9 persons

15 minutes → 27 persons

20 minutes → 81 persons

Using the formula:

3^20/5 =3^4 =81