Explanation

70 × 70 = 4900, and 4900 ÷ 100 = 49.

Last updated 14-feb-2026

Explanation

1 kilowatt-hour (kWh) is equivalent to 3.6 million joules (MJ).

As it represents the energy used when 1 kilowatt of power is consumed for 1 hour.

Explanation

The pattern of the series is obtained by adding 2, 2, 4, 18, ... (doubling the previous increment and adding 2).

2 + 2 = 4

4 + 2 = 6

6 + 4 = 10

10 + 18 = 28

28 + 54 = 82

Explanation

34, 24, 16, 10, 6

Find the differences between consecutive terms:

- 34 → 24 (−10)  

- 24 → 16 (−8)  

- 16 → 10 (−6)  

- 10 → 6 (−4)

You can see a decreasing pattern in differences:  

−10, −8, −6, −4

So the next difference should be: −2

6 − 2 = 4

Explanation

• The standard form of a quadratic equation is ax^^2+bx+c=0.
• a, b, and c are constants.
• a ≠ 0; otherwise, it would not be quadratic.
• The highest power of x is 2.
• Example: 2x^2 + 3x -5=0.

Last updated 25-07-2026 by NA

Explanation

Step 1: Identify the days of the week for the first few dates

• 1st = Monday
• 2nd = Tuesday
• 3rd = Wednesday
• 4th = Thursday
• 5th = Friday (1st Friday)

Step 2: Add 7 days for subsequent Fridays

• 2nd Friday = 5th + 7 = 12th
• 3rd Friday = 12th + 7 = 19th

Final Answer: The 3rd Friday is on the 19th of the month.

Explanation

When the velocity of an object is doubled, its kinetic energy becomes four times its original value.

This is because the kinetic energy formula (KE = 1/2 * mv²) shows that kinetic energy is directly proportional to the square of the velocity.

Therefore, doubling the velocity (2v)² results in a fourfold increase in kinetic energy. 

kinetic energy (ke) = ½mv²  

if velocity is doubled → ke = ½m(2v)² = ½m(4v²) = 4 times the original.

Explanation

When a sound wave moves from one medium to another, the quantity that remains the same is its frequency. 

The frequency of a sound wave is determined by the source of the sound and doesn't change when it enters a different medium.

However, the wavelength and speed of the wave can change depending on the properties of the new medium. 

Explanation

360 = 40x

x = 9 days

Explanation

- cos(90°) = 0  

- So, sin(θ) × cos(90°) = sin(θ) × 0 = 0