ABCD is a cyclic trapezium in which AD || BC. If ∠ABC = 70°, then ∠BCD is

• 110°

• 80°

• 70°

• 90°

If cos 27° = x, then value of 63° is

The sum of 10 terms of the arithmetic series is 390. If the third term of the series is 19, find the first term:

• 3

• 5

• 7

• 7

The average of marks obtained by 100 candidates in a certain examination is 30. If the average marks of passed candidates is 35 and that of failed candidates is 10, what is the number of candidates who passed the examination?

• 60

• 70

• 80

• 80

If a + b = 10 and ab = 21, then the value of (a - b)² is

• 15

• 16

• 17

• 17

If (x - 4) (x² + 4x + 16) = x³ - p, then p is equal to

• 27

• 8

• 64

• 64

G is the centroid of Δ ABC. If AG = BC, then measure of ∠BGC  is

• 45°

• 60°

• 90°

• 120°

In a circle, a chord 5√2 cm long, makes a right angle at the centre. Then the length of the radius of the circle will be

• 2.5 cm

• 5 cm

• 7.5 cm

• 10 cm

69.

If cos²x + cos⁴x = 1, then tan²x + tan⁴x = ?

• 0

• 1

• 2tan²x

• 2tan²x

The angle of elevation of aeroplane from a point on the ground is 45°. After flying 15 sec, the elevation changes to 30°. If the aeroplane is flying at a height of 2500 m, then the speed of the aeroplane in km/hr is

• 600

• 600( √3 + 1 )

• 600√3

• 600( √3 - 1 )