31. Two numbers x & y are such that the sum of 6% of x and 5% of y is \(\frac{3}{5}\) of the sum of 6% of x and 7% of y. Then find the ratio of x and y.
32. The ratio of number of boys to that of girls in a school is 5 : 1. If 70% of boys and 60% of girls are scholarship holders, then find the percentage of students who do not get scholarship.
33. The cost of manufacture of an article is made up of 4 components A, B, C and D which have a ratio of 1 : 2 : 3 : 4 respectively. If there are respective changes in the ost of 10%, -20%, -30%, -40%, then what will be the percentage change in the cost ?
34. The height of a triangle is increased by 20%. What could be maximum percentage increase in length of base whose area increases by 60%.
35. In an examination there are three subjects physics, chemistry and math having max marks 200, 120, 150 respectively. A student gets 50%, 70%, 60% in physics, chemistry, math respectively. If he wants to get 70% marks if four subjects then how many marks he must obtain in biology of max marks 200.
36. In an examination 500 girls and 1000 boys appeared. In which 50% girls and 40% boys passed the exam. Then find the % of failed students ?
37. In a class, the number of girls is 20% more than that of the boys. The strength of the class is 77. If 6 more girls are admitted to the class then find the ratio of the number of boys to that of the girls.
38. If 70% of the students in a school are girls and the number of boys is 570, how many girls are in school ?
39. Ankit invests 1000 Rs. in some share in the ratio 2 : 3 : 5 which pay dividends of 5%, 10% and 20% (on his investment) for that year respectively. Find the dividend income.
40. A batsman scored 130 runs which included 5 four and 5 sixes. What percentage of his total score did he make by running between the wickets ?
41. In a class, number of girls is more than the number of boys by 20% of the total strength. What is the ratio of boys to girls ?
42. The radius of sphere is 10 cm. Find out its surface area is how % of its volume?
43. A fruit seller had some apples. He sells 40% apples and stills has 360 apples. Then how much apples originally he had ?
44. A customer asks for the production of ‘a’ number of goods. The company produces ‘b’ number of goods daily, out of which c% units are for sale. Then in how many days order will be completed ?
45. The sujm of two numbers is 280. If the bigger number is decreased by 54% and the smaller number is increased by 15% then the number obtained are equal. Find the numbers.
46. The expences on wheat, Rice and sugar of a familuy are in the ratio 15 : 18 : 7. The price of theser articles are increased by 20%, 30% and 40% respectively. Then find the total increased expense of the family.
47. Due to an increase of 50% in the price of bananas, 4 bananas less are available for Rs. 24. What will be the present rate of per dozen bananas ?
48. 90% of boys in a school passed in Hindi, 50% passed in english and 240 boys passed in both the subjects. If no student failed in both the subjects, then find the total number of boys.
49. Ankit spents \( \boldsymbol{33\frac{1}{3}} \) of his salary on the item of daily use and 30% of the remainder on house rent. After that he is left with 1120 Rs. How much is his salary ?
50. A man spent 30% of an amount to buy grocery and10% of the remaining to transportation then he donated 90 Rs. If he is left with 1800. What is the amount spent on transport ?
51. If a man’s salary is 25% more than that of Naman, then how much percent is Naman’s salary less than that of
Aman ?
52. The price of rice rises by 20%. By how much percent should the consumption of rice be reduced so that the expenditure does not change.
53. If the duty of an article is reduced by 60% of its present rate, By how much percent must its consumption increase in order that the revenue remain unaltered ?
54. A number is first decreased by 20%. The decreased number is then increased by 20%. The resulting number is less than the original number by 40. Find the original number.
55. A number is first decreased by 20%. The decreased number is then increased by 20%. The resulting number is less than the original number by 40. Find the original number.
56. If the price of an article is first decreased by 20% and then increased by 25%. Then find the net percentage change.
57. If the price of an article is first increased by 20% and again increased by 10%. If the last increased price Rs. 198 then what was the original price.
58. If the length, breadth and height of a cube are decreased, increased, increased by 5%, 10% and 20% respectively. Then what will be the impact on the volume of cube.
59. While measuring the length of a rectangle it has been taken in 40% excess and its breadth was measured 40% less. Find the percentage change in its area.
60. Ram saves 15% of his salary while Shyam saves 32%. If both get the same salary and Shyam saves 2240 Rs. then what is the saving of Ram ?