# Question 4:

A train covers a distance of 480 km at a uniform speed. If the speed had been 8 km/h less, it would have taken 3 hours more to cover the same distance. Find the original speed of the train.Â  Â  Â  Â  Â  Â  Â  Â  [CBSEÂ  Â  2020]

## Solution:

Let the original speed of the trainÂ  = x km/h.

Time of journey of 480 km = hours

Time taken to cover a journey of 480 km with speed of (x – 8) km/h = hours

Now according to the question.

â‡’ x(x – 40) + 32(x – 40) = 0\$

â‡’Â  (x – 40)(x + 32) = 0

â‡’ x = 40,Â  -32(Not possible)

Thus the original speed of train is = 40 km/h.

# Question:1

If Ritu were younger by 5 years than what she really is, then the square of her age would have been 11 more than five times her present age. What is her present age ?Â  Â  Â  Â  Â  Â  Â  Â  Â  Â [CBSE Term-2 SQP 2022]

# Question 2:

The sum of areas of two squares is 157 mÂ². If the sum of their perimeters is 68 m, find the sides of the two squares.Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â [CBSE 2019]

# Question 3:

If the equation (1 + mÂ²)xÂ² + 2 mcx + cÂ² – aÂ² = 0 has equal roots then show that cÂ² = aÂ²(1 + mÂ²).

[CBSE 2017]

# Question 5:

In a flight of 600 km, an aircraft was slowed due to bad weather. Its average speed for the trip was reduced by 200km/hr and time of flight increased by 30 minutes. Find the original duration of flight .Â  Â  Â  [CBSEÂ  2020]

Solution :

# Question 6:

A train travels 360 km at a uniform speed. If the speed had been 5 km/hr more, it would have taken 1 hours less for the same journey. Find the speed of the train.Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â [CBSEÂ  2019]