The angle of elevation of the top of a tower $30$ $m$ high from the foot of another tower in the same plane is $60°$ and the angle of elevation of the top of the second tower from the foot of the first tower is $30°.$ The distance between the two towers in m times the height of the shorter tower. What is m equal to?

Find out which part of a sentence has an error:
It was he who (A) came running in the house (B) with the news about the earthquake. (C) No Error. (D)

Find out which part of a sentence has an error: 
Her mother does not approve of (A) her to go to the party (B) without dressing formally (C) No Error (D).

In the following questions, a group of our words is given in each group, one word is incorrectly spelt. Find the incorrectly spelt word.