Quantitative Aptitude - Arithmetic Ability Questions

A milkman buys milk at Rs 24 per litre. He adds 1/5 of water to it and sells the mixture at Rs 32 per litre. What will be his gain (in %)?

If A = (1/0.4) + (1/0.04) + (1/0.004) + ... upto 8 terms, then what is the value of A?

Ashok can row upstream at 8 kmph and downstream at 12kmph.What is the speed of the stream ?

P can do a work in 10 days. Q can do the same work in 15 days. If they work together for 5 days, how much of the work will they complete?

A wholesaler sells a watch to a retailer at a gain of 37% and the retailer sells it to a customer at a loss of 25%. If the customer pays Rs 2,620.125, what had it cost the wholesaler?

The average of the ages of Rajan and his son is 20. If Rajan's present age is three times the age of his son, then what will be the age of Rajan 5 years from now?

Akshar remembers that the match is after 26th April but before 30th April, while Suresh remembers that the match is after 22nd April but before 28th April. On which date of April is the match?

Rajeev sells a machine for Rs 55 lakhs at a loss. Had he sold it for Rs 67 lakh, his gain would have been 5 times the former loss. Find the cost price of the machine.