How to use de moivre’s theorem to express ⅙ sin 6θ / sin θ as a polynomial in cos θ?

Two pillars of equal height stand on either side of a road-way which is 60 m wide. At a point in the road-way between the pillars, the elevation of the top of the pillars is 60° and 30°. The height of the pillar is:

• A. 15√3 m
• B. 15/√3 m
• C. 15 m
• D. 20 m

Two distinct numbers are picked randomly from the first ten natural numbers. Find the probability that the L.C.M of the two numbers is 6.

How many two digit numbers are divisible by 5 such that remainder is 1.

How many two digit numbers are divisible by 4?

• A. 21
• B. 22
• C. 24
• D. 25