Question
A boat takes 5 hours longer to travel 15 km upstream
than it does to travel 20 km downstream. The speed of the boat in still water is 5 km/hr. Calculate the speed of the current.Solution
Let the speed of the current be x km/hr According to the question, 15/(5 β x) β 20/(5 + x) = 5 Or, x2Β + 7x β 30 = 0 Or, x2Β + 10x β 3x β 30 = 0 Or, x(x + 10) β 3(x + 10) = 0 Or, (x β 3) = 0 or, (x + 10) = 0 X = -10 km/hr not possible Therefore, x = 3 km/hr Hence, option b.
After interchanging Γ· and Γ , 4 and 8, which of the following equations becomes correct?
After interchanging '- ' and '+ ' , 6 and 7 , which of the following equations becomes correct?
...Which one of the following is correct?
28 * 7 * 8 * 10
Which of the following is correct?
If '+' means 'Γ·', 'Γ·' means 'β', 'β' means 'Γ', 'Γ' means '+', then ' 30 + 10 Γ· 6 β 5 Γ 6 ' = (?)
...The given equation has been solved on the basis of a certain rule. Find the correct answer for the unsolved equation on that basis.
If p × ...
A cube is made by following the given sheet. In the cube so formed, What would be the symbol on the opposite side of the # Symbol?
If β#β denotes β-β, @ denotes βΓβ, β$β denotes β+β and β%β denotes βΓ·β, thenΒ
20 $ 15 # 10 @ 45 % 15
...If 'P' denote 'Γ·', 'ΞΈ' denotes 'x', 'R' denotes '+' and 'S' denotes '-', what is the value of ' 18 ΞΈ 12 P 4 R 5 S 6 '.
Relevant for Exams:
