Question
The speed of the boat in still water is 20% less than
the speed of the boat in downstream. The time taken by the boat to cover 780 km distance in upstream is (t+3) hours. If the speed of the stream is 20 km/h, then find out the value of ‘t’.Solution
ATQ, Let ‘B’ be the speed of the boat in still water and ‘S’ the speed of the stream, with S = 20 km/h. B = (100-20)% of (B+S) = 80% of (B+S) = 0.8(B+S). B = 0.8(B+20), which leads to B = 0.8B + 16, thus 0.2B = 16, giving us B = 80 km/h. With the boat covering 780 km upstream, where upstream speed = B - S = 80 - 20 = 60 km/h, we have 780/(t+3) = 60. Solving for t yields t+3 = 780/60 = 13, Hence, t = 10. Value of ‘t’ = 10.
More Approximation Questions
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(1/5) of {5⁴ - 24 × 14 + 12 × 18 - 10.5 of 10²} 3% of 842 ÷ 2% of 421 = ?
√225 + 27 × 10 + ? = 320
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45 % of 180 + √144 * 8 = ?2 + 70 % of 80
Determine the value of 'p' in following expression:
720 ÷ 9 + 640 ÷ 16 - p = √121 X 5 + 6²- 7?2 = √20.25 × 10 + √16 + 32
- What will come in place of the question mark (?) in the following questions?
(2⁴ + 6²) ÷ 2 = ? 18(1/3) + 9(2/3) – 10(1/3) = 1(2/3) + ?
