First you have to find 10% of 340.00 which is 28, so each week he saves 28.00 for his bike. To find how many paychecks he has to recieve you divide 340.00 by 28.00, which is 12.1, since there is a decimal place you have to round it up to 13 because it is a little bit more than 12 paychecks. ;)