A. 6/63
B. 2/63
C. 125/126
D. 1/126
Explanation:
Required probability = 1 – 1/126 = 125/126
A. 96
B. 68
C. 72
D. 108
Let the number of boys and girls in the class be 11x and 13x. 4 boys and 8 girls join the class. Strength of the class
= 11x+13x+4+8
= 24x+12 (11x+4):(13x+8) = 4:5 5*(11x+4)=4*(13x+8) 55x+20=52x+32 3x=12 x=4 24x+12=108
A. 3
B. 2
C. 4
D. 6
Explanation:
(5 * 5)/5 + 1/5 * 5 = 5 + 1 = 6
A. 3.5km/hr
B. 5.75km/hr
C. 6.5km/hr
D. 7km/hr
Explanation:
Speed Downstream = 15.5 km/hr,
speed upstream = 8.5 km/hr
Speed of the stream = ½ (15.5 – 8.5)km = 3.5 km/hr
A. 400
B. 320
C. 240
D. 300
With a full tank, it can travel
360*4/3 = 480 km With 2/3 full tank, it can travel
480*2/3 = 320 km
A. -2, -1/2
B. 4, -1
C. 4, 1
D. -2, 5/2
Explanation:
2×2 + 4x + x + 2 = 0
2x(x + 2) + 1(x + 2) = 0
(x + 2)(2x + 1) = 0 => x = -2, -1/2
A. 20
B. 15
C. 25
D. 35
Let the number of students who wrote the exam be x.
Total marks of students = 80 x.
Total marks of (x – 5) students = 90(x – 5)
80x – (5 * 40) = 90(x – 5)
250 = 10x => x = 25