The purpose of this research was to study the appropriate teaching and learning style for developing mathematics knowledge. The samples of this study were 60 Bachelor Degree students major in package and textile design. The research instruments were the teaching and learning style for developing mathematics knowledge in analytical geometry questionnaire interview and attitude test. The data was analyzed by means of arithmetic mean standard deviation Peasons Product Moment Correlation and interpretation analysis.

Blends of R22/R152a/R124 have been proposed to replace R12 in refrigeration systems.In this research work a technique to simply evaluate thermodynamic properties of refrigerant mixtures has been developed from Raoults Law.the method has been approached to evaluate the properties of the refrigerant blends avalable in the market such as MP39( R22/R152/R124 53/13/34)MP52 (R22/R152a/R124 33/15/52)and MP66 (R22/R152/R124 61/11/28) .The results agree well with those given by the manufacture within 5 % error The method has also been used to evaluate the properties of the ( R32/R125/R134a 23/25/52)refrigerant agree wall with those given from the manufacture with in 3 % error The thermodynamic property dlagrams of these refrigerant blends are also proposed.