Solution: The hundred’s digit is twice the unit’s digit. Find the number

Solution: Find the smallest number which when

Solution: In the expansion of (x^2- 1/x^3)^30, find the term (or term free of x)

Solution: Mary is twice as old as Ana was when Mary was as old as Ana is now. How old is Ana?

Solution: If 396 were subtracted from the number, the order of the digits will be reversed. Find the number

Solution: How many of each type did he buy?

Solution: How much tin and how much lead can be added to 700 kg of an alloy

Solution: How long will the pipe be able to fill up the tank?

Solution: Suppose A = {2,4,6,8,10,12}, B = {1,4,9,16} and C = {2,10}

Solution: How long will Tito have to work with Ding?