Question
A motor boat goes downstream from point A to B ,which
is 36 km away from point A, and then returns to A.If actual speed of the boat in still water is 7km/hour ,and the total upstream and downstream journey takes 21 hours .What must be the actual speed of boat for the journey from A to B to take exactly 108 minutes ?Solution
Speed of boat in still water is 7km/hour Let the Speed of Stream be x Km/hour 36/(7+x) + 36/(7-x) = 21 24 = 49- x^2 x = 5 km/hour Now, the speed of Boat for the journey from A to B to take time 108 minutes is Speed of boat = y km/hour , Speed of stream =5km/hour , Time = 108 minutes (y+5) = (36×60)/108 = 20km/hour y+5 = 20 y = 15km/hour ∴ Speed of Boat must be 15km/hour
1242.12 ÷ √530 + 1139.89 ÷ 14.91 = ? + 45.39
? = 25.08 + 11.99 × 24.07
40 × 55.96 ÷ 7 – 20% of 699.81 + 63 = ? - (11479.50 ÷ 7)
25.902 × 78.095 + 999.996% of 200.08 + 20.005 % of 7999.997 = ? × 15.008 × 33.009
11.67 × 50.23 + ? = 14.88% of 600.44 + 9.66 × 8.272
78% of 1450 + 26² = ? + 1323 ÷ 17
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.)...
65.22 of 359.98% + 459.99 ÷ 23.18 = ?
- 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 will come in place of the question mark (?) in the following question? (Note: You are not expected to calculate the exact value.)...
