SSC CGL 201911)If the radius of a right circular cylinder is decreased by 20% while its height is increased by 40%, then the percentage change in its volume will be:
10.4% decrease
Volume of right circular cylinder =\( \pi r^2 h;\)
Now,
\(r_1 = 0.8r;
h_1 = 1.4h\);
Volume of right circular cylinder =\( \pi (0.8h)^2 \times 1.4h = 0.896\pi r^2 h;\)
Decrement in volume = \(\pi r^2 h - 0.896\pi r^2 h = 0.104\pi r^2 h\);
Percentage decrement in volume =\( \frac{0.104\pi r^2 h}{\pi r^2 h} \times 100 = 10.4%;\)
therefore The correct answer is option B.
SSC CGL 201912)Monika spends 72% of her income. If her income increases by 20% and savings increase by 15%, then her expenditure increases by: (correct to 1 decimal place)
21.9%
SSC CGL 201913)The price of oil is increased by 20%. However, its consumption decreased by \(8\frac{1}{3}\)% . What is the percentage increase or decrease in the expenditure on it?
Increase by 10%
SSC CGL 201914)Basir’s working hours per day were increased by 15% and his wages per hour were increased by 20%. By how much percent did his daily earnings increase?
38
SSC CGL 201915)If 25% of half of x is equal to 2.5 times the value of 30% of one-fourth of y, then x is what percent more or less than y?
50% more
SSC CGL 201916)In an examination, A obtained 10% more marks than B, B obtained 20% more marks than C and C obtained 32% less marks than D. If A obtained 272 marks more than C, then the marks obtained by B is:
1020
SSC CGL 201917)If 60% of a number is 120 more than 20% of the number, then 28% of the number is less than \(33\frac{1}{3}\)% of the number by:
16
SSC CGL 201918)In a class, \(83\frac{1}{3}\)% of the number of students are girls and the rest are boys. If 60% of the number of boys and 80% of the number of girls are present, then what percentage of the total number of students in the class are absent?
\(23\frac{1}{3} \)
SSC CGL 201919)A spends 65% of his income. His income is increased by 20.1% and his expenditure is increased by 25%. His savings:
Increase by 11%
SSC CGL 201920)If the price of petrol increases by 19%, and Sunita intends to spend only an additional 12% on petrol, by what percent should she reduce the quantity of petrol purchased (nearest to an integer)?
6