Aptitude Day 80

Ratio and Proportion:

1. Two numbers are in the ratio 9:10. If 2 is added to both, their ratio changes to 12:13. The smallest number is:

Solution:
               Let the numbers be 9x and 10x.
               (9x+2)/(10x+2) = 12/13
               117x+26 = 120x+24
               x = 2/3.
               The smallest number is 9x = 6.

2. 8900 were divided among x, y and z so that x:y = 4:5 and y:z = 6:7. Then, y gets:

Solution:
               x:y:z = 24:30:35
               Total parts = 99
                y = 30*(8900/99)
                y = 3000.