Introduction to Database Systems

Find the relational algebra statement for both parts.

Question 1. a. Which models of PCs sell for less than $700?

b. What are the model numbers of color laser printers?

The relation PC model |speedramhdprice 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 2.66 1024 250 2114 2.10512250 995 1.42 512 80 478 2.80 1024 250 649 3.20 512250 630 3.20 1024 320 1049 2.20 1024 200510 2.20 2048 250 770 2.00 1024 250 650 2.80 2048 300 770 1.86 2048 160 959 2.80 1024 160 649 3.06 512 80529 The relation Laptop model |speedramhdscreen price 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2.00 2048 240 1.73 1024 80 1.80 51260 2.00512 60 2.16 1024 120 2.00 2048 80 1.83 1024 120 1.60 1024 100 1.60 51280 2.00 2048 160 20.13673 17.0949 15.4 549 13.31150 17.0 2500 15.4 1700 13.3 1429 15.4900 14.1 680 15.4 2300 The relation Printer model otypeprice 3001 tru ink-jet 3002 falselaser 3003 true lase 239 899 120 120 100 200 true ink-jet 3005 false laser 3006 tru ink-jet 3007 true lase The relation Product makermodeltype 1001 pc 1002 pc 1003 pc 2004 laptop 2005 laptop 2006 laptop 1004 pC 1005 pc 1006 pc 2007 laptop 1007 pc 1008 pc 1009 pc 1010 PC 3004 printer 3005 printer 1011 pc 1012 pc 1013 pc 2001 laptop 2002 laptop 2003 laptop 3001 printer 3002 printer 3003 printer 2008 laptop 2009 laptop 2010 laptop 3006 rinter 3007 inter