Question
A boat covers 32 km upstream and 40km downstream in 8
hours while it covers 40km upstream and 32 km downstream in 8.5 hours. What is the velocity of current?Solution
Let the speed of upstream be x km/hr Speed of downstream = y km/hr 32/x + 40/y = 8 ………….(i) 40/x + 32/y = 8.5…………………….(ii) Adding (i) and (ii), we get 72 (1/x + 1/y) = 33/2 …………..(iii) Subtract (i) from (ii), we get 8 (1/x - 1/y) =0.5 …………..(iv) Adding (iii) and (iv), we get 2/x = 33/144 + 1/16 2/x = 42/144 x = 48/7 km/hr Now, 7/48 - 1/y = 1/16 y = 12 km/hr Now, rate of current = 1/2 (12 - 48/7) = 18/7 km/hr
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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