If 4 , 31 , 92 , and y are in proportion, then the value of y is:

The monthly incomes of two friends Ajay and Amit, are in the ratio 5 : 7 respectively and each of them saves Rs. 72000 every month. If the ratio of their monthly expenditure is 2 : 4, find the monthly income of Ajay(in Rs.).

The mean proportional between 0.09 and 16 is:

The mean proportional between $$\left(9 + 4\sqrt{5}\right) \text{ and } \left(18 - 8\sqrt{5}\right) \text{ is:}$$​