You are making sets of pens and pencils to sell. you want each set to contain the same combination of pens and pencils. you have 105 pens and 147 pencils, and you want to use them all. what is the greatest number of these sets you can make?

Expresa commuter train leaves downtown sation and travels at a average speed of 55 miles per hour towards the north side sation, which is 50miles away. thirty minutes later, express commuter train #7 leaves north side and travels at a average speed of 35miles per hour towards downtown sation. at the moment the two trains pass each other, how far(in miles) is train #12 from the downtown sation and how long(in minutes) has the #12 train been traveling