SSC CGL 202011)In a school, 4 % of the students did not appear for the annual exams. 10% of the students who appeared for the exams could not pass the exam. Out of the remaining students, 50% got distinction marks and 432 students passed the exam but could not get distinction marks. The total number of students in the school is:
1000
Let total number of students be x. According to the question, 50%of 90% of 96% of x = 432 ; ⇒ x = 1000
SSC CGL 202012)The price of sugar is increased by 20%. By what percentage must one cut down on the consumption of sugar, so that no extra amount has to be incurred on sugar?
\(16{2\over3}\)%
Required percent = \({20\over100+20}\times100 = 16{2\over3}\)%
SSC CGL 202013)A and B spend 60% and 75% of their incomes, respectively. If the savings of A are 20% more than that of B. then by what percentage is the income of A less than the income of B?
25
Let the income of A and B be X and Y respectively.
Saving of A = \(X - \frac{60}{100} \times X\) = 0.4X;
Saving of B = \(Y - \frac{75}{100} \times Y = 0.25Y\);
If the savings of A are 20% more than that of B then,
Saving of A = \(0.25Y \times \frac{120}{100} = 3Y/10\); ⇒ 0.4X = 3Y/10; ⇒ 4X = 3Y;
Ratio of income of A and B = 3 : 4 ;
Required percentage = \(\frac{(4 - 3)}{4} \times100\) = 25%
SSC CGL 202014)In an examination in which the full marks were 500, A scored 25% more marks than B, B scored 60% more marks than C and C scored 20% less marks than D. If A scored 80% marks, then the percentage of marks obtained by D is :
50%
Let D's marks be x. C's marks = 80% of x = \({4x\over5}\) ;
B's marks = 160% of \({4x\over5}\) = \(32x\over25\) ;
A' marks = 125% of \(32x\over25\) = \(8x\over5\) ;
According to the question : \({8x\over5}=\) 80% of 500 ; ⇒ x = 250 ;
Required percent = \({250\over500}\times100\) = 50%