A random variable X has the probability distribution:

• 0.87

• 0.77

• 0.35

• 0.35

The mean and the variance of a binomial distribution are 4 and 2 respectively. Then the probability of 2 successes is

• 37/256

• 219/ 256

• 128/256

• 128/256

73.

If the straight line y = mx + c (m > 0) touches the parabola y² = 8(x + 2), then the minimum value taken by c is

• 12

• 8

• 4

• 4

The equation of the plane which contains the line of intersection of the planes x + y + z – 6 = 0 and 2x + 3y + z + 5 = 0 and perpendicular to the xy plane is:

• x – 2y + 11 = 0

• x + 2y + 11 = 0

• x + 2y – 11 = 0

• x + 2y – 11 = 0

The curve y = (λ + 1)x² + 2 intersects the curve y = λx + 3 in exactly one point, if λ equals -

• {–2, 2}

• {1}

• {-2}

• {-2}