Question
A train crosses a 300-metre-long bridge in 20 seconds,
and the same train crosses a tunnel twice the length of the bridge in 35 seconds. Find the speed of train in km/h.Solution
Let the length and speed of train be ‘l’ metres and ‘x’ m/s, respectively.
Then, according to question,
(l + 300)/20 = (l + 600)/35
7l + 2100 = 4l + 2400
3l = 300
l = 100 metres
x = (l + 300)/20 = 400/20 = 20 m/s = 20×(18/5) = 72 km/h
What approximate value will come in place of the question mark (?) in the following question? (Note: You are not expected to calculate the exact value.)...
5999.93 ÷ 60.005 × 70.002 = ? × 24.9
?% of 309.99 = 40.01% of 249.99 + 295.98% of 49.99
16.11 × 9.96 – (238.19 – 64.04 × 2.18) = ?
20.06% of 359.89 - 15.95 X ? + 18.07 X 14.95 = 48.87 X 6.02
2550.03 ÷ 74.98 x 49.9 = ? + 20.32
56237.05 + 10616.99 - 137.25 + 1795.33 = ?
- What approximate value will come in place of the question mark (?) in the following question? (Note: You are not expected to calculate the exact value.)
30.33% of 440.08 + 45.09 × 5.998 – √961.09 × 3.990 – 189.99 = ?
44.87% of (39.85 × ?) – 1520.88 0.51 = 1400.8
