British Journal of Mathematics & Computer Science 10(2): 1-8, 2015, Article no.BJMCS.18825 ISSN: 2231-0851 SCIENCEDOMAIN international www.sciencedomain.org Solving Interval Linear Equations with Modified Interval Arithmetic Mehdi Allahdadi 1∗ and Zohreh Khorram 1 1 Mathematics Faculty, University of Sistan and Baluchestan, Zahedan, Iran. Article Information DOI: 10.9734/BJMCS/2015/18825 Editor(s): (1) Drago - Patru Covei, Department of Mathematics, University Constantin Brancusi of Targu-Jiu, Romania. Reviewers: (1) Anonymous, Rajshahi University of Engineering and Technology, Bangladesh. (2) Anonymous, Jaypee Institute of Information Technology, Noida, India. (3) Anonymous, Kwame Nkrumah University of Science and Technology, Ghana. (4)Anonymous, University of Namk Kemal, Turkiye. Complete Peer review History: http://sciencedomain.org/review-history/10078 Short Research Article Received: 11 May 2015 Accepted: 05 June 2015 Published: 07 July 2015 Abstract Gaussian elimination method is one of the widely used methods for solving linear equations. An interval version of Gaussian elimination method has been used by simply replacing each real arithmetic step by the corresponding interval arithmetic step. Two interval arithmetics technique has been considered for modified interval arithmetics as well as several existing interval arithmetics. In this paper, modified interval arithmetic has been introduced based on two interval arithmetics technique. If we solve interval linear system of equations by existing interval arithmetic method the replacing solution in interval system of equations, the interval width is more than the interval width of right hand side intervals. On the other hand, applying modified interval arithmetic the interval width is less than interval width than previously obtained by existing interval arithmetic. Moreover, the closeness of interval width in system of equations to the right hand side is important so modified interval arithmetic is more effective and efficient for solving interval linear system of equations. Keywords: Existing interval arithmetic; interval linear equations; modified interval arithmetic. 2010 Mathematics Subject Classification: 65G40; 15A06 *Corresponding author: E-mail: m allahdadi@math.usb.ac.ir