Question
A boat travels the same distance 'd' km in both upstream
and downstream directions, taking a total of 15 hours for the round trip. If the downstream speed of the boat is 16 km/hr and the upstream speed is 8 km/hr, calculate the time required for the boat to cover '1.5d' km in still water.Solution
ATQ, d/16 + d/8 = 15 Or, {d + 2d)/16} = 15 Or, 3d = 15 X 16 Or, 3d = 240 So, 'd' = (240/3) = 80 Speed of boat in still water = average of speed of boat in downstream and in upstream = (16 + 8)/2 = 12 km/hr  So, required time = 80 x 1.5/12 = 10 hrsÂ
(31.9)3 + (34.021)² - (16.11)3 - (42.98)² = ?
- 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.)
What approximate value should come in the place of question mark in the following questions?
(598.5 ÷ 29.9) + (401.2 ÷ 20.1) = ?
(16.16 ×  34.98) + 14.15% of 549.99 = ? + 124.34
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.)...
960.02 of 238.89 ÷ 144.01 of 79.97 = ?
- 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.)
320.98 + 49.99% of (261.09 + 138.98) = ?
? = 29.91% of 49.94% of ((56.25 × 4.09 + 23.01 × 7.89) × 99.98)
20.02% of (95.96 × 104.01 – 56.02 × 64.04) – ? = 12.02 × 39.96 + 103.03Â
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