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SSC Selection Post 2020 PYQ — Question 61

SSC Selection Post - Matriculation Level 2020 - 10 Nov 2020 - Shift 1 • Quantitative Aptitude • Q61

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A car travels a distance of x km at a speed of 5595\over9 m/s and returns at a speed of 5 m/s to the starting point. If the total time taken by the car is 3161\over6  hours, then the value of x is:

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Correct answer: B

Explanation

The correct answer is option 2 i.e. 30.

Total time in seconds:  19 / 6 hours = 19 / 6 × 3600 = 11400 seconds

59=509\frac{5}{9} = \frac{50}{9} m/s (already in fraction form)

time = distance/speed

⇒ x×100050/9+x×10005=11400\frac{x \times 1000}{50/9} + \frac{x \times 1000}{5} = 11400

⇒ 1000x50/9=1000x⋅950=9000x50=180x\frac{1000x}{50/9} = \frac{1000x \cdot 9}{50} = \frac{9000x}{50} = 180x 

⇒ 1000x5=200x\frac{1000x}{5} = 200x

So total time:

180x+200x=11400⇒380x=11400⇒x=11400380=30180x + 200x = 11400 \Rightarrow 380x = 11400 \Rightarrow x = \frac{11400}{380} = 30 km