✅ Answer Key & Solutions
Q1
B
P(A∪B) = P(A)+P(B)−P(A∩B) = 0.35+0.45−0.15 = 0.65
Q2
A
Standard quadratic formula: x = (−b ± √(b²−4ac)) / 2a
Q3
A
D = b²−4ac = 4 − 12 = −8
Q4
C
By BPT: AD/DB = AE/EC → 3/5 = 6/EC → EC = 10 cm
Q5
B
sin 30° = ½; cos 60° = ½; sum = 1
Q6
A
Hyp = √(9+16) = 5; sin θ = opp/hyp = 3/5
Q7
B
Area of equilateral triangle = (√3/4)a²
Q8
A
(x−3)(x−4) = 0; x = 3 or 4
Q9
B
Sum = n(n+1)/2; Mean = n(n+1)/2 ÷ n = (n+1)/2
Q10
B
tan 60° = h/200 → √3 = h/200 → h = 200√3 m
Q11
B
SSS similarity criterion: all corresponding sides proportional → triangles similar
Q12
B
Substitute x=2: k(4) − 5(2) + 2 = 0 → 4k − 10 + 2 = 0 → 4k = 8 → k = 2
Q13
C
Sorted: 74,78,85,88,90,92,96. Median (4th) = 88
Q14
C
Pythagorean identity: sec²θ − tan²θ = 1
Q15
B
Hypotenuse² = Sum of squares of other two sides
Q16
A
Deviations from 70: -10,-5,2,10,-15,20,-2. Sq: 100,25,4,100,225,400,4. Sum=858. Var=858/7≈122.6≈124 (closest)
Q17
B
Sum of roots = −b/a
Q18
C
tan 45° = 1; cot 45° = 1; sum = 2
Q19
C
h² = 10² − 6² = 100 − 36 = 64 → h = 8 m
Q20
D
sin θ ranges from 0 to 1 for θ ∈ [0°, 90°]