## Saturday, 15 September 2012

### Pair of Linear Equations in two variables MCQ X CBSE Mathematics

 Pair of Linear Equations in two variables MCQ X CBSE Mathematics 1. The number of solutions of the pair of linear equations x + 2y – 8 = 0 and 2x + 4y = 16 is : (a) 0 (b) 1 (c) infinitely many (d) none of these 2. The graphical representation of the pair of equations x + 2y – 4 = 0 and 2x + 4y – 12 = 0 represents : (a) intersecting lines (b) parallel lines (c) coincident lines (d) all of these 3. If a pair of linear equations is consistent, then the lines will be : (a) parallel (b) always coincident (c) intersecting or coincident (d) always intersecting 4. The condition so that the pair of linear equations kx + 3y + 1 = 0, 2x + y + 3 = 0 has exactly one solution is : (a) k = 6 (b) k ≠ 6 (c) k = 3 (d) k ≠ 3 5. The lines representing the linear equations 2x – y = 3 and 4x – y = 5 : (a) intersect at a point   (b) are parallel (c) are coincident (d) intersect at exactly two points 6. The pair of linear equations 2x + 5y = –11 and 5x + 15y = –44 has : (a) many solutions (b) no solution (c) one solution (d) two solutions 7. The pair of equations y = 0 and y = –7 has : (a) one solution (b) two solutions (c) infinitely many solutions (d) no solution 8. If the lines given by 3x + 2ky = 2 and 2x + 5y + 1 = 0 are parallel, then the value of k is : (a) –5/4 (b) 2/5 (c) 15/4 (d) 3/2 9. The pair of linear equations 8x – 5y = 7 and 5x – 8y = –7 have : (a) one solution (b) two solutions (c) no solution (d) many solutions 10. The pair of linear equations x – 2y = 0 and 3x + 4y = 20 have : (a) one solution (b) two solutions (c) many solutions (d) no solution 11. The pair of linear equations kx + 2y = 5 and 3x + y = 1 has unique solution, if : (a) k = 6 (b) k ≠ 6 (c) k = 0 (d) k has any value 12. One equation of a pair of dependent linear equations is –5x + 7y = 2, the second equation can be : (a) 10x + 14y + 4 = 0 (b) –10x = 14y + 4 – 0 (c) –10x + 14y + 4 = 0 (d) 10x – 14y = –4 13. The value of k for which the pair of equations : kx – y = 2 and 6x – 2y = 3 has a unique solution is (a) k = 3 (b) k ≠ 3 (c) k ≠ 0 (d) k = 0 14. The value of k for which the pair of linear equations 4x + 6y – 1 = 0 and 2x + ky – 7 = 0 represents parallel lines is : (a) k = 3 (b) k = 2 (c) k = 4 (d) k = –2 15. If x = a, y = b is the solution of the equations x – y = 2 and x + y = 4, then the values of a and b respectively are (a) 3 and 5 (b) 5 and 3 (c) 3 and 1 (d) –1 and –3