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Ratio
Question 136 [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER] |
Two natural numbers are in the ratio 3 : 5 and their product is 2160. The smaller of the numbers is -
18 | |
36 | |
24 | |
12 |
Question 136 Explanation:
Let the numbers be 3x and 5x
Then, = 3x $\times$ 5x = 2160
⇒ 15x2 = 2160
⇒ x2 = 144
⇒ x = 12 ∴ Smaller number = 3x = 3 $\times$ 12 = 36
Question 137 [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER] |
The fourth proportion to 5, 8, 15 is-
18 | |
21 | |
20 | |
24 |
Question 137 Explanation:
Let the fourth proportional to 5, 8, 15 be x.
Then, \begin{align} & \Rightarrow 5:8:15:x \cr & \Rightarrow 5x = 8 \times 15 \cr & \Rightarrow x = \frac{{8 \times 15}}{5} = 24. \cr\end{align}
Question 138 [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER] |
In a mixture of 25 litres the ratio of acid to water is 4 : 1. Another 3 litres of water of water is added to the mixture. The ratio of acid to water in the new mixture is =?
2 : 5 | |
5 : 2 | |
5 : 3 | |
3 : 5 |
Question 138 Explanation:
\begin{align} & {\text{Acid}}:{\text{Water}} \cr & \, \, \, \, \, 4\, \, \, \, \, :\, \, \, \, \, \, \, 1 \cr & {\text{Let }}4x + x = 5x \cr & \because 4x + x = 25 \cr & \Rightarrow x = 5 \cr & \therefore {\text{Acid }} = {\text{ }}5 \times 4 = 20 \cr & {\text{Water }} = 5 \times 1 = 5 \cr & \therefore {\text{3 Litres water is added }} \cr & {\text{So, new quantity of water}} \cr & = 5 + 3 = 8 \cr & \therefore {\text{Acid}}:{\text{Water}} \cr & \, \, \, \, \, \, \, \, \, {\text{20}}\, \, \, :\, \, \, \, \, \, \, 8 \cr & \, \, \, \, \, \, \, \, \, \, \, 5\, \, \, \, :\, \, \, \, \, \, \, 2 \cr\end{align}
Question 139 [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER] |
A box filled with paper bundles weights 36kg. If the weight of the box and paper bundles respectively are in the ratio of 3 : 22 then the weight of the papers (in grames) is =?
31500 garms | |
30680 garms | |
31680 garms | |
30710 garms |
Question 139 Explanation:
| Box | : | Paper bundle | |
| Weight | 3 | : | 22 |
| Let | 3x | : | 22x |
25x = 36kg
\begin{align} & x = \frac{{36}}{{25}} \times 1000 \cr & \, \, \, \, \, = 1440{\text{ garms}} \cr\end{align} (∴ 1kg = 1000 grams)
∴ Weight of paper bundles = 22x
= 22 $\times$ 1440 garms = 31680 garms
Question 140 [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER] |
Rita invested 25% more than sunil. Sunil invested 30% less than Abhinav, who invested Rs. 6000. What is the ratio of the amount that Rita invested to the total amount by all of them together?
35 : 103 | |
101 : 36 | |
13 : 29 | |
35 : 104 |
Question 140 Explanation:
\begin{align} & {\text{Abhinav's investment}} \cr & = {\text{Rs}}{\text{. 6000}}. \cr & {\text{Sunil's investment}} \cr & = \left( {100 - 30} \right)\% {\text{ of Rs}}{\text{. 6000}} \cr & = {\text{70}}\% {\text{ of Rs}}{\text{. 6000}} \cr & = {\text{Rs}}{\text{.}}\left( {\frac{{70}}{{100}} \times 6000} \right) \cr & = {\text{Rs}}.4200. \cr & {\text{Rita's investment}} \cr & = \left( {{\text{100 + 25}}} \right)\% {\text{ of Rs}}{\text{. 4200}} \cr & = {\text{125}}\% {\text{ of Rs}}{\text{. }}42{\text{00}} \cr & = {\text{Rs}}{\text{.}}\left( {\frac{{125}}{{100}} \times 4200} \right) \cr & = {\text{Rs}}{\text{. }}5250. \cr & {\text{Total amount invested}} \cr & = {\text{Rs}}{\text{.}}\left( {{\text{6000}} + 42{\text{00}} + 5250} \right) \cr & = {\text{Rs}}{\text{. }}15450. \cr & \therefore {\text{Required Ratio}} \cr & = 5250:15450 \cr & = 35:103. \cr\end{align}
There are 140 questions to complete.