Linear Equations in two variables-MCQ

1.  Customers are asked to stand in the lines. If one customer is extra in a line, then there would be two less lines. If one customer is less in line, there would be three more lines. Find the number of students in the class.
       (a)  40
       (b)  50
       (c)  60
       (d)  70
2.  8 girls and 12 boys can finish work in 10 days while 6 girls and 8 boys can finish it in 14 days. Find the time taken by the one girl alone that by one boy alone to finish the work.
       (a)  120, 130
       (b)  140,280
       (c)  240,280
       (d)  100,120
3.  The sum of two digits and the number formed by interchanging its digit is 110. If ten is subtracted from the first number, the new number is 4 more than 5 times of the sum of the digits in the first number. Find the first number.
       (a)  46
       (b)  48
       (c)  64
       (d)  84
4.  A fraction becomes . when subtracted from the numerator and it becomes . when 8 is added to its denominator. Find the fraction.
       (a)  4/12
       (b)  3/13
       (c)  5/12
       (d)  11/7
5.  Five years ago, A was thrice as old as B and ten years later, A shall be twice as old as B. What is the present age of A.
       (a)  20
       (b)  50
       (c)  60
       (d)  40
6.  What will be the solution of these equations ax+by=a-b, bx-ay=a+b
       (a)  x=1, y=2
       (b)  x=2,y=-1
       (c)  x=-2, y=-2
       (d)  x=1, y=-1
7.  If x=a, y=b is the solution of the pair of equation x-y=2 and x+y=4 then what will be value of a and b
       (a)  2,1
       (b)  3,1
       (c)  4,6
       (d)  1,2
8.  Rozly can row downstream 20km in 2 hours, and the upstream 4km in 2 hours. What will be the speed of rowing in still water?
       (a)  6km/hr
       (b)  4km/hr
       (c)  3km/hr
       (d)  7km/hr
       1. c
       2. b
       3. c
       4. c
       5. b
       6. d
       7. b
       8. a