A wholesaler sells a good to a retailer at a profit of 5% and the retailer sells it to a customer at a profit of 10%. If the customer pays Rs. 2,000, what had it cost (in Rs) the wholesaler?
A and B together do a job in 12 days and A could do the job in 20 days if he worked alone. How many days would B take to do the job if he worked alone?