Question
The ratio of the speed of boats ‘A’ and ‘B’ in
still water is 8:9, respectively. The speed of the current is 25% of the speed of boat ‘A’ in still water. If boat ‘A’ takes 9 hours to travel 810 km downstream, then find the time taken by boat ‘B’ to travel 252 km upstream and 792 km downstream. (Note: Both the boats are rowing in the same stream.)Solution
Let the speeds of boats ‘A’ and ‘B’ in still water be 8x km/hr and 9x km/hr Therefore, speed of the current = 0.25 × 8x = 2x km/hr According to the question, 8x + 2x = 810/9 Or, 10x = 90 Or, x = 9 Therefore, upstream speed of boat ‘B’ = 9x – 2x = 7x = 63 km/hr Downstream speed of boat ‘B’ = 9x + 2x = 11x = 99 km/hr Required time taken = (252/63) + (792/99) = 4 + 8 = 12 hours
√9604 + ∛205379 + 58% of 1500 = 520 + ?
9 × 40 × 242 × 182 = ?2
19 × ? = 361 ÷ 19
72 × 2 = ? + 104 – 14
12.5% of 384 - 16.66% of 66 = √16 + √? + 22
What will come in the place of question mark (?) in the given expression?
? X 7 + (243)⁽²/⁵⁾ = 380 ÷ 2 + 71(30% of 400 - 20% of 540 + 35% of 1000) = ?
120% of 400 + ?% of 520 = 1000
{(522 – 482 ) ÷ (27 + 73)} × 35 = ?% of 175
