Question

plzzz...... give me solution of these question...

Answer 1

Let the speed of the second train = x km/hr
The speed of the first train = x+2 km/hr
Distance covered after two hours by the first train is 2(x+35) km.

hence

Distance covered by the second train after two hours is 2x km.
1302 = (2x)2 + [2(x + 35)]2
⇒ 16900 = 4x2 + 4(x2 + 70x + 1225)
⇒ 16900 = 8x2 + 280x + 4900
⇒  8x2 + 280x – 12000 = 0
⇒  x2 + 35x – 1500 = 0
⇒  x2 + 60x – 25x  – 1500 = 0
⇒  x(x + 60) – 25(x  + 60) = 0
⇒  (x + 60)(x – 25) = 0
⇒  (x + 60) = 0 or (x – 25) = 0
∴ x = –60 or x = 25
Since x cannot be negative, x = 25
(x + 35) = 25 + 35 = 60
Thus the speed of first train = 25 kmph
Speed of second train = 60 kmph