Question
A train running with a speed of 45 km/hr can cross a
pole in 10 seconds and a platform in 20 seconds. Find the length of the platform.Solution
Speed of the train = 45 × (5/18) = 12.5 m/sec Length of the train = 12.5 × 10 = 125 metres Let the length of the platform be ‘x’ metres Therefore, 125 + x = 12.5 × 20 Or, x = 250 – 125 = 125 metres
Simplify:
5x + 7y - [(10x + 4y) - (3x + 2y) + 5y] - 3xIf a = 2 + √3, then the value of (a6 + a4 + a2 + 1)/a3 is
If √z + (1/√z) = 14, then find the value of z + (1/z).
What will come in place of the question mark (?) in the following series?
23, 46, ?, 184, 368, 736
A man covered 40 km by bus and rest 25 km on foot. If the speed of the bus is 150% more than that of the man and the whole distance is covered in 2 hour...
If a + b + c = 6, a² + b² + c² = 14 and ab + bc+ ca = 11, then what is the value of a³ + b³ +c³ –3abc?
Length of each side of a rhombus is 13 cm and one of the diagonal is 24 cm. What is the area (in cm2) of the rhombus?
For which value of k does the quadratic equation
x² − 4(k + 1)x + (3k² + 8k + 4) = 0
have equal real roots?
- If a 2  + b 2  + c 2  = 240 and ab – bc – ca = 64, then find the value of (a + b – c) 2 .
