What least number must be subtracted from 1936 so that the resulting number when divided by 9, 10 and 15 will leave in each case the same remainder 7 ?

Answer: Option C

$$\begin{array}{rl}& \text{LCM of }\left(9,10,15\right)\\ & =3\times 3\times 10\\ & =90\\ & \frac{1936}{90},\text{remainder = 46}\end{array}$$
Least number when is subtracted from 1936 which gives remainder 7 when divided by (9, 10, 15) is = (46 - 7) = 39