Question
A train travels from A to B at a speed of 60 km/h, and
then from B to C at a speed of 80 km/h. The total distance covered from A to C is 240 km, and the total time taken is 3.5 hours. What is the distance between B and C?Solution
Let the distance from A to B be x km, and the distance from B to C be (240 - x) km. Time taken to travel from A to B = x / 60, Time taken to travel from B to C = (240 - x) / 80. The total time taken is 3.5 hours, so: x / 60 + (240 - x) / 80 = 3.5. Multiply through by 240 (LCM of 60 and 80) to eliminate the denominators: 4x + 3(240 - x) = 840, 4x + 720 - 3x = 840, x = 120. Thus, the distance between B and C is 240-120 = 120 km.
If (x2 + y2) = 9 and (xy)2 = 3, then find the value of (x4 + y4).
√4096 + √(?) + 13 – 29 = 148Â
If √r + (1/√r) = 4, then find the value of r + (1/r).

If x = 99, then the value of x5 - 100x4 + 100x3 - 100x2 + 100x - 1 is
Find the value of
(1 - Â `1/(p+1)` ) + (1 - `2/(p+1)` Â ) + (1 - `3/(p+1)` Â ) + ........................... + (1 - Â `p/(p+1)` )
If a + b + c = 8, a² + b² + c² = 18 and ab + b c+ ca = 12, then what is the value of a³ + b³ +c³ –3abc?
If (a + b) = 9 and (a2 + b2) = 53, then find the value of (a × b).
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The graphs of the equations 3x-20y-2=0 and 11x-5y +61=0 intersect at P(a,b). What is the value of (a² + b² − ab)/(a² − b²...