CLASS XD HOMEWORK

PAIR  OF  LINEAR EQUATIONS IN TWO VARIABLES

1.       If the pair of linear equations   x – y = 1 and x + ky = 5  has a unique solution  x = 2,     y = 1 then  value of k is

             a )  - 2                 b)   3                  c)  - 3               d)  4

2.       The pair of equations  3x + 4y = k;   9x + 12y = 6     has infinitely many solutions if

            a ) k = 2                 b)  k = 6                  c)  k   ≠  6               d)  k = 3

3.       The pair of linear equations   3x + 5y = 3   and   6x + ky = 8   do not have any              solution if

        a )   k = 5                b)  k = 10                  c)  k   ≠  10               d)  k ≠ 5

4.       The unique solution for the pair of linear equations    x + 2y =5   and 7x + 3y = 13 is

a)      x = 1, y = 2       b) x = 2, y = 1           c) x = 3, y = 1                       d) x = 1, y =  3

5.       If  ( 5 , k ) is a solution of 2x + y -  6 = 0,  then the value of k is equal to

           a )  6                    b)   4                     c)  - 3                      d)  - 4

6.       If  a + b = 5 and 3a + 2b = 20, then 3a + b will be

           a )  25                b)   20                  c)  15               d)  10

7.       If     x  + y = 6   and     3x – y = 4, then  x – y    is equal      to

           a )  - 1                 b)   0                  c)  2               d)  4

8.       The system of equations    x + 2y = 3  and  2x + 4y = 3 has

           a)exactly two solutions  b) no solution c) infinitely many solutions d) a unique solution

9.       The equations 3x – 4y = 5   and 12x – 16y = 20  have

          a)more than two solutions b)exactly two solutions c)exactly one solution d) no solution

   10.   The equations 2x + y = 5  and x + 2y = 4 are

      a) consistent and have a unique solution b) consistent and have infinitely many solutions

         c) inconsistent                                                  d)  None of these

   11.    The condition for which the system of equations  kx – y = 2 and 6x – 2y = 3 has a

              unique  solution is

        a)      k = 0         b) k ≠ 0          c) k = 3       d)  k ≠ 3

12.   3 chairs and 2 tables cost   Rs 700 while  5 chairs and 3 tables  cost Rs 1100. What              is the   cost of   2 chairs and 2 tables ?

      a)      Rs 350          b)   Rs 600            c) Rs 650        d) Rs 675

    13.   The difference between two numbers is  5 and the difference  between their squares               is 65. The larger number is

     a)      9       b)   10                 c)  11            d)  12

    14.   A man has some hens and  cows.  If the number of heads be 48 and the number of              feet

            equals  140, the number of  hens will be

      a)       22          b)  23                c)   24          d) 2