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
Which one among the following is the smallest?
The ratio of length to breadth of a rectangle is 8:5. When the length and breadth of the rectangle is increased by 22% and decreased by 30% respectively...
A box has 80 Red, 40Blue and 40 Black Balls. 25% of Red Balls and 50% of Blue Balls are taken away, percentage of Black balls at present is
The side of a square is equal to the perimeter of an equilateral triangle of area 196√3 cm2 . Find the area of the square?Â
A rectangular piece of copper foil of length 63 cm and area 1386 cm2 is folded along its width to form a cylinder such that there is only one...
A square and a rhombus lie on a common base and the rhombus is inclined at an angle of 30° with the base. Find the ratio of the areas of the square and...
The perimeters of two similar triangles, ∆ PQR and ∆ XYZ are 48 cm and 24 cm respectively. If XY = 12 cm. then PQ is:
The cost of painting the walls of a room 8 meter long and 10 meter wide at Rs 22.5 square per meter is 7290. What is the height of the room?
Mr. Vivek divides Rs. 1703 such that 4 times the 1st share, thrice the 2nd share and twice the third share amount to the same. Then the value of the 2nd...
The perimeter of a square is the same as that of a rectangle with length 18 cm and width 10 cm. What will be the circumference of a semicircle whose rad...