Question
A train travelling with a speed of 90 km/h can cross a
pole in 8 seconds. Find the time taken by the train to cross a 300 metres long platform if the speed of train is increased by 25%.Solution
Speed of train = 90 × 5/18 = 25 m/s Length of train = 25 × 8 = 200 metres Desired time = (300 + 200)/(1.25 × 25) = 16 seconds
If the sum of the coefficients in the expansion of (a + b)n is 16384, then the greatest coefficient in the expansion is

The perimeter of a rectangular field is 34 metres and its area is 60 m2 . What is the length of the diagonal of this field?
If the sum of the coefficients of all even powers of x in the product (1 + x + x2 + … + x2n) (1 – x + x2 – x...
A certain number of books were distributed equally among a group of students in a class. Each student received a number of books equal to one-fifth of t...

Find the coefficient of x⁴ in (2x – 3/x)⁶.

Find both the maximum value and the minimum value respectively of 3a4 minus; 8a3 + 12a2 minus; 48a + 25 on the interval...