Question
The speed of current is 4 km/h. What will be the
respective downstream speed and upstream speed of a boy rowing a boat, if half of the distance covered going downstream in a certain time is equal to the distance covered going upstream in the same time?Solution
Let the speed of boy in still water be X km/h. And the speed of current = 4 km/h Downstream speed = (X + 4) km/h Upstream speed = (X – 4) km/h Let time be ‘t’ hours. ⇒ [(X + 4) t]/2 = (X – 4) t ⇒ X + 4 = 2X – 8 ⇒ X = 12 km/h Downstream speed = 12 + 4 = 16 km/h Upstream speed = 12 – 4 = 8 km/h
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.)...
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