Explanation

Time at original speed = 240 / x  

Time at increased speed = 240 / (x + 4)  

Given:  

240/x - 240/(x + 4) = 0.5

Multiply through by x(x + 4) to eliminate denominators:

240(x + 4) - 240x = 0.5x(x + 4)  

240x + 960 - 240x = 0.5x² + 2x  

960 = 0.5x² + 2x  

Multiply both sides by 2:  

1920 = x² + 4x  

x² + 4x - 1920 = 0

Solve the quadratic:  

x² + 4x - 1920 = 0  

Using quadratic formula:  

x = [-4 ± √(16 + 7680)] / 2  

x = [-4 ± √7696] / 2  

√7696 ≈ 87.7  

x ≈ (-4 + 87.7)/2 ≈ 83.7/2 ≈ 41.85

Approximate correct option is 40 km/h

Explanation

We are given:

- 3rd term = 8  

- 6th term = 17  

- We need to find the 8th term.

Formula for nth term of an AP:  

Tₙ = a + (n - 1)d

Let’s form equations:

1) T₃ = a + 2d = 8  

2) T₆ = a + 5d = 17  

Subtract (1) from (2):  

(a + 5d) - (a + 2d) = 17 - 8  

⇒ 3d = 9  

⇒ d = 3  

Now plug back to find a:  

a + 2(3) = 8  

⇒ a + 6 = 8  

⇒ a = 2

Now find the 8th term:  

T₈ = a + 7d = 2 + 7(3) = 2 + 21 = 23

Explanation

Let's try to find the consistent difference between numbers:

- 54 → 43 → difference = -11  

- 43 → 34 → difference = -9  

- 34 → 26 → difference = -8  

- 26 → 22 → difference = -4  

- 22 → 19 → difference = -3  

- 19 → 18 → difference = -1

The differences are not follow a regular pattern.

Now assume correct pattern:  

Try subtracting odd numbers in decreasing order:

- 54 - 11 = 43  

- 43 - 9 = 34  

- 34 - 7 = 27  

- 27 - 5 = 22  

- 22 - 3 = 19  

- 19 - 1 = 18

So if the intended pattern was subtracting odd numbers in sequence (11, 9, 7, 5, 3, 1):

The correct sequence should be:  

54, 43, 34, 27, 22, 19, 18

So the number 26 in the original sequence is wrong.  

It should have been 27 instead of 26.

Correct wrong number: 26  

Correct sequence: 54, 43, 34, 27, 22, 19, 18

Explanation

2√(x + 2) = 3√2

Step-by-step solution:

Step 1: Divide both sides by 2

√(x + 2) = (3√2)/2

Step 2: Square both sides

x + 2 = [(3√2)/2]²  

= (9 × 2) / 4  

= 18 / 4  

= 4.5

Step 3: Subtract 2 from both sides

x = 4.5 − 2  

x = 2.5

Explanation

Let the number be x.  

40% of x = 380  

⇒ (40/100) × x = 380  

⇒ 0.4x = 380  

⇒ x = 380 ÷ 0.4  

⇒ x = 950

Explanation

Fibonacci sequence: next number is sum of previous two → 8 + 13 = 21

Explanation

 (10 + 20) ÷ 2 = 15

Explanation

 Pattern is ×2 + 1 → (4×2+1 = 9),

(9×2+1 = 19),

(19×2+1 = 39),

(39×2+1 = 79)

Explanation

A person walks:

- 3 km North

- 4 km East

- 3 km West

Net East-West movement = 4 km East - 3 km West = 1 km East  

North movement = 3 km

Distance from the starting point = √(3² + 1²) = √(9 + 1) = √10 ≈ 3.16 km

So, the person is approximately 3.16 km away from the starting point.

Explanation

The result of 15 × 6 ÷ 2 is:

15 × 6 = 90  

90 ÷ 2 = 45