Question
The speed of a boat in still water is 40% higher than
the speed of the stream. The boat takes 4 hours to travel 96 km downstream. If the boat's speed in still water is decreased by (100/7)% , determine the distance the boat can cover upstream in 6 hours.Solution
ATQ, Let the speed of the stream be '10p' km/h. So, the speed of the boat in still water = 1.4 × 10p = '14p' km/h. According to the question, 14p + 10p = 96/4 Or, 24p = 24 Thus, 'p' = 1. The speed of the stream = 10p = 10 km/h. Now, the reduced speed of the boat in still water = 14p × (6/7) = 12 km/h. Therefore, the required distance = (12 - 10) × 6 = 12 km.
[564 + 32 of 18 × 9 ÷ 12 + 162 ] ÷ 4 = ?
Evaluate: (936 ÷ 12) × (225 ÷ 15) − (144 ÷ 12) × 18
- What will come in place of the question mark (?) in the following questions?
0.5×120+25=? [(4 √ (7) + √ (7)) × (7 √ (7) + 6 √ (7))] - 87 = ?
...√(24²+285-8²-172) = ?²
20% of 10% of 900 + 84/12 = ?2
?² = 37% of 800 – 14 × 18+ 5! - 20
(18 × 9 ÷ 6) × 3 = ?
- What will come in place of (?), in the given expression.
144 ÷ 12 + 18 × 2 = ?