There are 40000 students in 4 colleges of a city If half of the first two third of the second three ...........

Quantitative Aptitude (CDS) Ratio, Proportion

There are 40000 students in 4 colleges of a city. If half of the first, two-third of the second, three-fourth of the third and four-fifth of the fourth are the same number of students, then find the ratio of the number of students of K and N if K, L, M, and N be the first, second, third and fourth schools respectively?

7:4

8:5

6:5

9:5

Explanation:

K/2 = 2L/3 = 3M/4 = 4N/5
Therefore, K/L = 4/3 and L/M = 9/8 and M/N = 16/15
K:L = 4:3
L:M = 9:8
M:N = 16:15
K : L : M : N = (16×4×9) : (3×16×9) : (3×8×16) : (15×3×8)
K : L : M : N = 576 : 432 : 384 : 360
Therefore the ratio of the number of students of K and L = 576: 360
= 8 : 5