Uses of Ratios and Proportions

Q.

The ratio of Copper and Zinc in an alloy is $7:8$. If the weight of zinc is $12.8kg$, find the weight of copper in the alloy?

Q. The angles of a pentagon are in the ratio $5:4:5:7:6$ ; find each angle of the pentagon.

Q.

Ravi had 16 chocolates with him. He gave 3 chocolates to Ali. What is the ratio of chocolates given to Ali to the total chocolates Ravi had?

1. 3: 19

2. 19: 3

3. 3: 16

4. 16: 3

Q. The width of a Indian letter is $5\times {10}^{-1}$ mm. A pack of Indian letters have a width of 10m. How many Indian letters are there in the pack?

1. 20000

Q. PQNM and ZYXW are two rectangular doors used for the main door and a cupboard. Find the ratio of their sides.

1. $\frac{MN}{WX}=\frac{NO}{XY}=\frac{OP}{YZ}=\frac{PM}{ZW}=3$
2. $\frac{MN}{WX}=\frac{NO}{XY}=\frac{OP}{YZ}=\frac{PM}{ZW}=2$
3. $\frac{MN}{WX}=\frac{NO}{XY}=\frac{OP}{YZ}=\frac{PM}{ZW}=4$
4. $\frac{MN}{WX}=\frac{NO}{XY}=\frac{OP}{YZ}=\frac{PM}{ZW}=5$

Q. A train X starts from Meerut at $4$ PM and reached Delhi at $5$ PM. While another train starts from Delhi at $4$ PM and reaches Meerut at $5:30$. The two train will cross each other at ?

1. $4:36$ PM
2. $4:42$ PM
3. $4:48$ PM
4. $4:50$ PM

Q. Total population of a city is 8000, out of which 6000 are males. What percentage of the total population are males (in %)?

1. 75

Q.

The length and breadth of a rectangle are in the ratio 6 : 5 and its perimeter is 110 m. The area of the rectangle is ___ $c{m}^2$

1. 750

2. 650

3. 700

4. 800

Q. After sales tax, a book costs $\$25.20$. If sales tax is $5\%$, how much does the book cost before taxes?

1. $\$23.50$
2. $\$24.00$
3. $\$23.94$
4. $\$26.46$
5. $\$24.23$

Q. The area of the shaded portion in the graph shown below represents

1. Time
2. Speed
3. None of these
4. Distance

Q.

In a dinner, there is enough meal for 200 children or 120 men. If 140 children had finished their meal, how many men can be catered to with the remaining meal? [ 3 MARKS ]

Q. Nancy pays $6\%$ sales tax on a car that costs $\$22,000$. What is the cost of the car including sales tax?

1. $\$23,320$
2. $\$23,540$
3. $\$24,200$
4. $\$31,200$
5. $\$35,200$

Q. The number that must be added to each of the numbers $8,21,13$ and $31$ to make the ratio of first two numbers equal to the ratio of last two numbers is

1. $7$
2. $9$
3. $5$
4. $3$

Q. Ratio of number of boys to number of girls in a tutorial is $2:3$. If there are $180$ girls the number of boys is

1. $60$
2. $36$
3. $100$
4. $120$

Q. Match the following cards, which have two different figures, with their correct ratios:

1. 
2. 
3. 3 : 2
4. 
5. 3 : 7
6. 3 : 4

Q. The amount of work in a leather factory is increased by $50\%$. By what percent is it necessary to increase the number of workers to complete the new amount of work in previously planned time, if the productivity of the new labour is $25\%$ more.

1. $66\frac{2}{3}\%$
2. $60\%$
3. $40\%$
4. $33\frac{1}{3}\%$

Q. In a college, the ratio of the number of boys to girls is 8 : 5. If there are 200 girls, the total number of students in the college is

1. 670
2. 480
3. 520
4. 300