Ratio and Proportion

Q21. If a: b = c : d = e : f = 1 : 2 then (3a + 5c + 7e) : (3b + 5d + 7f) = ?
(a) 1 : 2
(b) 2 : 3
(c) 3 : 4
(d) 4 : 5

Q22. The ratio of earnings of A and B is 8 : 9. If the earnings of A increase by 50% and the earnings of B decrease by 25%, the new ratio of their earnings is 16 : 9. What are A's earnings ?
(a) Rs. 1800
(b) Rs. 2600
(c) Rs. 3300
(d) Not sufficient data

Q23. In a school, the ratio of boys and girls is 4 : 5. When 100 girls leave the school, the ratio becomes 6 : 7. How many boys are there in the school ?
(a) 900
(b) 1000
(c) 1200
(d) 1500

Q24. Two numbers are respectively 20% and 50% more than a third number. These two numbers are in the ratio
(a) 2 : 5
(b) 3 : 5
(c) 4 : 5
(d) 4 : 7

Q25. When 20% of a number is added to another number, the number increases by 50%. What is the ratio between the first and second number ?
(a) 5 : 2
(b) 5 : 7
(c) 7 : 3
(d) 9 : 5

Q26. The ratio of the ages of two students is 3 : 2. One is older than the other by 5 years. What is the age of the younger student ?
(a) 11 years
(b) 12 years
(c) 15 years
(d) 19 years

Q27. Vessels A and B contains mixtures of milk and water in the ratio 4:5 and 5:1 respectively. In what ratio should quantities of mixtures be taken from A to B to form a mixture in which milk to water is in the ratio 5 : 4 ?
(a) 1 : 2
(b) 3 : 4
(c) 3 : 5
(d) 5 : 2

Q28. If 3A = 2B and 5C = 4B, then A:C = ?
(a) 4 : 5
(b) 4 : 3
(c) 5 : 6
(d) 6 : 7

Q29. Find the fourth proportional to 3, 5 and 9
(a) 11
(b) 15
(c) 18
(d) 25

Q30. If a : b = 2 : 3, b : c = 3 : 4, c : d = 4 : 5, find a : b : c : d
(a) 3 : 5 : 12 : 15
(b) 4 : 5 : 12 : 15
(c) 4 : 7 : 12 : 15
(d) 6 : 9 : 12 : 15

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