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Ratio
Question 111 [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER] |
If A : B : C = 2 : 3 : 4, then ratio A/B : B/C : C/A is equal to?
8 : 9 : 12 | |
8 : 9 : 16 | |
8 : 9 : 24 | |
4 : 9 : 12 |
Question 111 Explanation:
\begin{align} & {\text{A}}:{\text{B}}:{\text{C}} = 2:3:4 \cr & {\text{Let }} \cr & {\text{A}} = 2x, {\text{B}} = 3x, {\text{C}} = 4x \cr & \therefore \frac{{\text{A}}}{{\text{B}}}:\frac{{\text{B}}}{{\text{C}}}:\frac{{\text{C}}}{{\text{A}}} = \frac{{2x}}{{3x}}:\frac{{3x}}{{4x}}:\frac{{4x}}{{2x}} \cr & \Rightarrow \frac{2}{3}:\frac{3}{4}:\frac{2}{1} \cr\end{align} Multiply by the L.C.M of denominator to remove fraction \begin{align} & {\text{So, }} \cr & {\text{L}}{\text{.C}}{\text{.M of }}\left( {3, 4, 1} \right) = 12 \cr & \therefore \frac{{\text{A}}}{{\text{B}}}\, \, \, \, \, :\, \, \, \, \, \frac{{\text{B}}}{{\text{C}}}\, \, \, \, \, \, :\, \, \, \, \, \frac{{\text{C}}}{{\text{A}}} \cr & \frac{2}{3} \times 12:\frac{3}{4} \times 12:\frac{2}{1} \times 12 \cr & \, \, \, \, \, \, \, 8\, \, \, \, \, \, \, :\, \, \, \, \, \, \, 9\, \, \, \, \, \, \, :\, \, \, \, \, \, \, 24 \cr\end{align}
Question 112 [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER] |
If x : 7.5 = 7 : 17.5, then the value of x is -
3.5 | |
3 | |
1 | |
2.5 |
Question 112 Explanation:
\begin{align} & = x:7.5 = 7:17.5 \cr & \Rightarrow 17.5x = 7.5 \times 7 \cr & \Rightarrow x = \frac{{7.5 \times 7}}{{17.5}} \cr & = 3. \cr\end{align}
Question 113 [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER] |
A policeman starts to chase a thief. When the thief goes to steps the policeman moves 8 steps and 5 steps of the policeman are equal to 7 steps of the thief. The ratio of the speed of the policeman and the thief is =?
25 : 28 | |
25 : 26 | |
28 : 25 | |
56 : 25 |
Question 113 Explanation:
The distance covered by policeman in 5 steps is equal to that of thief in 7 steps
⇒ 5P = 7T
P : T
7 : 5 (distance covered in each step)
⇒ And policeman goes 8 steps while thief moves 10 steps
| Policeman | : | Thief | ||
| Steps | 8 | : | 10 | |
| Distance in each step | 7 | : | 5 | |
| 56 | : | 50 | ||
| Speed | = | 28 | : | 25 |
Question 114 [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER] |
If Rs.1066 are divided among A, B, C and D such that A : B = 3 : 4, B : C = 5 : 6 and C : D = 7 : 5, Who will get the maximum?
D | |
C | |
B | |
A |
Question 114 Explanation:
\begin{align} & {\text{A}}:{\text{B}} = {\text{3}}:{\text{4}}, \cr & {\text{B}}:{\text{C}} = {\text{5}}:{\text{6}} \cr & \, \, \, \, \, \, \, \, \, \, \, \, \, = \left( {5 \times \frac{4}{5}} \right):\left( {6 \times \frac{4}{5}} \right) \cr & \, \, \, \, \, \, \, \, \, \, \, \, \, = 4:\frac{{24}}{5}, \cr & {\text{C}}:{\text{D}} = {\text{7}}:{\text{5}} \cr & \, \, \, \, \, \, \, \, \, \, \, \, \, \, = \left( {7 \times \frac{{24}}{{35}}} \right):\left( {5 \times \frac{{24}}{{35}}} \right) \cr & \, \, \, \, \, \, \, \, \, \, \, \, \, \, = \frac{{24}}{5}:\frac{{24}}{7}. \cr & \therefore {\text{A}}:{\text{B}}:{\text{C}}:{\text{D}} \cr & = 3:4:\frac{{24}}{5}:\frac{{24}}{7} \cr & = 105:140:168:120. \cr\end{align} Clearly, C will get the maximum.
Question 115 [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER] |
The Lucknow-Indore Express without its rake can go 24 km an hour, and the speed is diminished by a quantity that varies as the square root of the number of wagon attached. If it is known that with four wagons its speed is 20 km/h, the greatest number of wagons with which the engine can just move is
144 | |
140 | |
143 | |
142 |
Question 115 Explanation:
Speed = 24- k $\sqrt{n}$;
Putting the value, n = 4;
we get, k = 2.
Now the equation (as k = 2) become, S = 24-2 $\sqrt{n}$;
Thus, it means when n = 144, speed will be zero. Hence, train can just move when 143 wagons are attached.
There are 115 questions to complete.