(a+b+c) = 3+4+7 = 14 and
c = 7
Then, (a+b+c):c = 2:1.
The number of students in 3 classes is in the ratio 2:3:4. If 12 students are increased in each class this ratio changes to 8:11:14. The total number of students in the three classes in the beginning was
Let the number of students in the classes be 2x, 3x and 4x respectively;
Total students = 2x+3x+4x = 9x.
According to the question,
(2x+12)/(3x+12) = 8/11
24x+96 = 22x+132
Or, 2x = 132-96
Or, x = 36/2 = 18
Hence, Original number of students,
9x = 9*18 = 162.
A box has 210 coins of denominations one-rupee and fifty paise only. The ratio of their respective values is 13:11. The number of one-rupee coin is