In $\triangle ABC$ with AB = 5 cm, BC = 12 cm, AC = 13 cm and $\angle B = 90^\circ$, which of the following is/are not correct?

(a) $\tan C = \frac{12}{13}$

(b) $\text{cosec} A = \frac{13}{12}$

(c) $\sin B = \frac{5}{13}$

(d) $\tan A = \frac{12}{15}$

(e) $\cos C = \frac{12}{13}$

Choose the correct answer from the options given below:

The angle of elevation of the top of an unfinished tower at a distance of 75m from its base is 30°. How much higher must the tower be raised so that the angle of elevation of its top at the same point may be 60°?

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