Question
The total number of students in a college is 13,200. If
the number of male students increases by 30% and the number of female students increases by 20% in a year and after the increase total number of students in the college is 16,440, what is the difference between the initial number of male and female students in the college ?Solution
Let, the initial no. of male students be X . X × 130% + (13,200 – X ) × 120% = 16,440 ⇒ 1.30 X + 15,840 – 1.20 X = 16,440 ⇒ 0.10 X = 600 ⇒ X = 6,000 No. of female students = 13,200 – 6,000 = 7,200 Required difference = 7,200 – 6,000 = 1,200 Or Use Alligation Net increase in Population = `(16440-13200)/(13200)xx 100 = 3240/13200 xx 100 = 270/11%` Male Female 20% 30% Net Change% = 270/11% So New Values, Male Female 220 330 Net Change = 270
Shruti is currently 20% younger than Suhana. In four years, the age difference between them will change so that Suhana’s age will be to Shruti’s age...
Present age of A is 50% more than that of B. Present age of C, who is 6 years older than B, is 24 years. After how many years from now, ratio of ages of...
P got married 8 years ago. His present age is 5/3 times his age at the time of his marriage. P’s sister was 10 years younger to him at the time of...
"Amit and Bishnu's current ages are in the ratio 4:5. Chintu's age is 40% more than Amit's age. If Bishnu and Chintu's ages sum up to 106 years, what is...
The average age of the husband, wife and their child 4 years ago was 24 years and that of the husband and the child 5 years ago was 19 years. The prese...
Present age of ‘A’ is 40% more than that of ‘B’. If 11 years hence from now, ‘B’ will be 5 years younger than ‘A’, then find the sum of ...
2n years ago, the age of Rahul was four times that of his son and n years ago, the age of Rahul was thrice that of his son. If n years later, the sum of...
Sum of the present ages of A, B, C and D is 70 years. After 5 years ratio of their ages is 5:4:4:2. What is C’s present age?
A’s age is 160% of what he was 4 years ago, But 80% of what it will be after 4 years. What is his present age?
'P' and 'Q' have present ages in the ratio of 4:5. If Q’s current age is increased by 20%, the gap between their ages becomes 1...