Explanation

Selling price (SP) = Rs. 40.00

Profit percentage = 15%

Cost price (CP) = SP / (1 + 15/100)

= 40 / 1.15

= Rs. 34.78

To earn a 20% profit:

New selling price (SP) = CP * (1 + 20/100)

= 34.78 * 1.20

= Rs. 41.74

The correct answer is 41.74.

Explanation

Amount of work done by A and B in 1 day = 1/30

Amount of work done by A and B in 20 days = 20 × (1/30) = 20/30 = 2/3

Remaining work – 1 – 2/3 = 1/3

A completes 1/3 work in 20 days

Amount of work A can do in 1 day = (1/3)/20 = 1/60

=> A can complete the work in 60 days

Explanation

Let's say the number of girls is G and the number of boys is B.

3/4G = 1/2B

Given that the total number of pupils is 1420:

G + B = 1420

Solving the equations, we get B = 852.

The correct answer is 852.

Explanation

The pattern of the series is:

+1, +2, +3, +4, +5...

So, the next difference should be +6:

16 + 6 = 22

The correct answer is 22.

Explanation

Let A's current age be x and B's current age be y.

Since A is twice as old as B, x = 2y.

Three years ago, A's age was x - 3 and B's age was y - 3.

Since A was three times as old as B, x - 3 = 3(y - 3).

Solving the equations, we get x = 12.

So, the correct answer is 12 years.

Explanation

The pattern of the series is:

+3, +7, +11, +15, +19...

So, the next difference should be +23:

57 + 23 = 80

The correct answer is 80.

Explanation

Square (regular quadrilateral):

all four sides are of equal length (equilateral), and all four angles are right angles. 

A triangle that has no equal sides and no equal angles is known as a Scalene Triangle

while 

if two sides of a triangle are of equal length, then it is called. Isosceles triangle

Explanation

(9 + 43 - 4) = 48

48 ÷ 24 = 2

2 - 2 = 0

So, the correct answer is 0.

Explanation

8 cars / 18 minutes = x cars / 180 minutes (3 hours)

x = (8 * 180) / 18

x = 80

So, the correct answer is 80.

Explanation

3+1 = 4

4+3 = 7

7+1 = 8

8+3 = 11

11+1 = 12

12+3 = 15