New Learning Composite Mathematics SK Gupta Anubhuti Gangal Class 7 Percentage and Its Applications Self Practice 8F Solution
(1) 55 per cent of the students in a school are girls. What percentage of the students are boys? Find the number of students, if there are 216 boys.
(2) If 10% is deducted from a bill, Rs. 7200 remains to be paid. How much is the bill?
(3) Calculation gives the length of a line segment as 6.4 cm, while from drawing and measurement it is obtained as 6.6 cm. Find the error per cent.
(4) Atul deposited 30% of his income in a bank. After spending 50% of the remaining, he had Rs. 10,500 left with him. What is his income?
(5) Manish obtained 498 marks out of 600 marks and Aravind scored 640 marks out of 800 marks. Whose performance is better?
(6) In a graduate class of 200, 40% are women and 1/5 becomes lecturers. If the number of men who became lecturers is twice that of women, calculate approximate percentage of men who became lecturers.
(7) The price of an article is reduced by 25%. In order to retain the original price, by what percentage should the present price be increased?
(8) In a mixture of milk and water, the proportion of water by weight is 75%. If in the 60 g mixture, 15 g of water is added, what would be the percentage of water?
(9) One litre of water is evaporated from a 6 litre solution containing 4% sugar. Find the percentage of sugar in the remaining solution.
(10) State Electricity Board gives 15% discount on electricity bills, if it is paid before due date. A person gets Rs. 54 as discount. What was the actual amount of the bill?