Chapter 3: Pair of Linear Equations in Two Variables
Part – 1
1. The pairs of equations x+2y-5 = 0 and -4x-8y+20=0 have:
(a) Unique solution
(b) Exactly two solutions
(c) Infinitely many solutions
(d) No solution
Answer: (c) Infinitely many solutions
2. If a pair of linear equations is consistent, then the lines are:
(a) Parallel
(b) Always coincident
(c) Always intersecting
(d) Intersecting or coincident
Answer: (d) Intersecting or coincident
3. The pairs of equations 9x + 3y + 12 = 0 and 18x + 6y + 26 = 0 have
(a) Unique solution
(b) Exactly two solutions
(c) Infinitely many solutions
(d) No solution
Answer: (d) No solution
4. If the lines 3x+2ky – 2 = 0 and 2x+5y+1 = 0 are parallel, then what is the value of k?
(a) 4/15
(b) 15/4
(c) ⅘
(d) 5/4
Answer: (b) 15/4
5. If one equation of a pair of dependent linear equations is -3x+5y-2=0. The second equation will be:
(a) -6x+10y-4=0
(b) 6x-10y-4=0
(c) 6x+10y-4=0
(d) -6x+10y+4=0
Answer: (a) -6x+10y-4=0
6. The solution of the equations x-y=2 and x+y=4 is:
(a) 3 and 1
(b) 4 and 3
(c) 5 and 1
(d) -1 and -3
Answer: (a) 3 and 1
7. A fraction becomes 1/3 when 1 is subtracted from the numerator and it becomes 1/4 when 8 is added to its denominator. The fraction obtained is:
(a) 3/12
(b) 4/12
(c) 5/12
(d) 7/12
Answer: (c) 5/12
8. The solution of 4/x+3y=14 and 3/x-4y=23 is:
(a) ⅕ and -2
(b) ⅓ and ½
(c) 3 and ½
(d) 2 and ⅓
Answer: (a) ⅕ and -2
9. Ritu can row downstream 20 km in 2 hours, and upstream 4 km in 2 hours. Her speed of rowing in still water and the speed of the current is:
(a) 6km/hr and 3km/hr
(b) 7km/hr and 4km/hr
(c) 6km/hr and 4km/hr
(d) 10km/hr and 6km/hr
Answer: (c) 6km/hr and 4km/hr
10. The angles of cyclic quadrilaterals ABCD are: A = (6x+10), B=(5x)°, C = (x+y)° and D=(3y-10)°. The value of x and y is:
(a) x=20° and y = 10°
(b) x=20° and y = 30°
(c) x=44° and y=15°
(d) x=15° and y=15°
Answer: (b) x=20° and y = 30°