Of the three numbers, the first is twice the second, and the second is twice the third. The average of the reciprocal of the numbers is 7/12. The numbers are:

1/2 of A = 2/5 of B = 1/3 of C, then A:B:C is: 

A can do a piece of work in 5 days and B in 4 days. How long will they take to do the same work when working together

The sum of the present ages of father and son is 90 years. 10 years earlier the ratio of their ages was 5:2. The present age of the father is:

A person spends 25% of his annual income on house rent, 15% on education of children and 45% on other items. If he saves INR 14400 annually, then the person's total income is:

A man sells an article at a loss of 10%. If he had sold it for INR 75 more he would have gained 20%. The cost price of the article is (in Rs.):