Study the following data carefully and answer the questions:Five boat...
From the pie chart
X + Y = 360° – 54° – 90° – 67.5°
X + Y = 148.5° --------------(1)
Since, value of ‘X’ is a multiple of 7 but neither less than 49 nor more than 63.
So, possible values of X are 49, 56 and 63.
Case I:
If value of X = 49
So, value of Y = 148.5 – 49 = 99.5
Since, 99.5 is not a multiple of 9.5.
So, case I can be neglected.
Case II:
If value of X = 56
So, value of Y = 148.5 – 56 = 92.5
Since, 92.5 is not a multiple of 9.5.
So, case II can be neglected.
Case III:
If value of X = 63
So, value of Y = 148.5 – 63 = 85.5
Since, 92.5 is a multiple of 9.5.
So, case III cannot be neglected.
So, X = 63 and Y = 85.5
Let speeds of boats A, B, C, D and E in still water are ‘54a’ km/h, ‘90a’ km/h, ‘63a’ km/h, ‘67.5a’ km/h and ‘85.5a’ km/h respectively.
So, speed of stream = 12.5% of 90a = ‘11.25a’ km/h
Since, downstream distance covered by boat A in 5 hours is 5 km more than upstream distance covered by boat B in 4 hours.
(54a + 11.25a) * 5 – (90a – 11.25a) * 4 = 5
326.25a – 315a = 5
a = 5/11.25
Speed of stream = 11.25 * (5/11.25) = 5 km/h
Answer: B
Speed of boat B in still water = 40 km/h
Speed of boat D in still water = 30 km/h
Speed of stream = 5 km/h
Total downstream distance covered by the person:
(40 + 5) * (20/60) + (30 + 5) * 1.2 = 15 + 42 = 57 km
Distance covered by the person by boat D while coming back:
(30 – 5) * 1.44 = 36 km
Distance to be covered by the person by boat B in ‘t’ minutes while coming back = 57 – 36 = 21 km
So, value of ‘t’ = [21/(40 – 5)] * 60 = 36 minutes