India’s No.1 Educational Platform For UPSC,PSC And All Competitive Exam
  • Sign Up
  • Login
  • 0
Ratio and Proportion
1.If a:b:c = 3:4:7, then the ratio (a+b+c):c is equal to

Answer:Option 1

Explanation:

Solution:
(a+b+c) = 3+4+7 = 14 and
c = 7 Then, (a+b+c):c = 2:1.

Discuss in forum

2.The number of students in 3 classes is in the ratio 2:3:4. If 12 students are increased in each class this ratio changes to 8:11:14. The total number of students in the three classes in the beginning was

Answer:Option 1

Explanation:

Solution:
Let the number of students in the classes be 2x, 3x and 4x respectively;
Total students = 2x+3x+4x = 9x.
Accordingtothequestion,(2x+12)(3x+12)=81124x+96=22x+132Or,2x=13296Or,x=362=18Nence,Originalnumberofstudents,9x=9×18=162

Discuss in forum

3.A box has 210 coins of denominations one-rupee and fifty paise only. The ratio of their respective values is 13:11. The number of one-rupee coin is

Answer:Option 1

Explanation:

Solution:
Respective ratio of the number of coins;
= 13:11*2 = 13:22
Hence, Number of 1 rupee coins;
= 13*210/(13+22) = 78.

Discuss in forum

4.If A and B are in the ratio 3:4, and B and C in the ratio 12:13, then A and C will be in the ratio

Answer:Option 1

Explanation:

Solution:
(AB)×(BC)=(34)×(1213)Or,AC=3652=9:13

Discuss in forum

5.The salaries of A, B and C are in the ratio 1:3:4. If the salaries are increased by 5%, 10% and 15% respectively, then the increased salaries will be in the ratio

Answer:Option 1

Explanation:

Solution:
Let A's Salary = Rs. 100
Then, B's Salary = Rs. 300
And, C's Salary = Rs 400
Salary has given in 1:3:4 ratio.
Now,
5% increase in A's Salary,
A's new Salary = (100 + 5% of 100) = Rs. 105.
B's Salary increases by 10%, Then,
B's new Salary = (300 + 10% of 200) = Rs. 330.
C's Salary increases by 15%,
C's new Salary = (400 + 15% of 400) = Rs. 460.
Then, ratio of increased Salary,
A:B:C = 105:330:460 = 21:66:92.

Alternative
100(A's salary)===5%↑===> 105(A's increased salary);
300 (B's salary)===10%↑===>330 (B's increased salary);
400 (C's salary)===15%↑===> 460 (C's increased salary).
Ratio of their increased salary = 105:330:480 = 21:66:92

Discuss in forum

6.If A:B = 2:3 and B:C = 4:5 then A:B:C is

Answer:Option 1

Explanation:

Solution:

A/B = 2/3;
B/C = 4/5;
A:B:C = 2*4:3*4:3*5 = 8:12:15.

Discuss in forum

7.If two times A is equal to three times of B and also equal to four times of C, then A:B:C is

Answer:Option 1

Explanation:

Solution:
2A=3BOr,B=(23)A;and2A=4COr,C=(12)A;Hence,A:B:C=A:2A3:A2=1:22:12=6:4:3

Discuss in forum

8.Two numbers are in ratio 4:5 and their LCM is 180. The smaller number is

Answer:Option 1

Explanation:

Solution:
Let two numbers be 4x and 5x;
their LCM = 180 and HCF = x; Now,
1st number * 2nd number = LCM*HCF
Or, 4x*5x = 180*x;
Or, 20x = 180;
Or, x = 9;
then, the smaller number = 4*9 = 36.

Discuss in forum

9.If A:B = 2:3, B:C = 4:5 and C:D = 5:9 then A:D is equal to:

Answer:Option 1

Explanation:

Solution:
AD=(AB)×(B×C)×(CD)=(23)×(45)×(59)=(2×4×5)(3×5×9)=827=8:27

Discuss in forum

10.In a class, the number of girls is 20% more than that of the boys. The strength of the class is 66. If 4 more girls are admitted to the class, the ratio of the number of boys to that of the girls is

Answer:Option 1

Explanation:

Solution:
Girls:boys = 6:5;
Hence, girls = 6*66/11 = 36;
Boys = 30;
New ratio, 30:(36 + 4) = 3:4.

Discuss in forum

Page 1 Of 20