A group of 1200 persons consisting of captains and soldiers is travelling in a train. If for every 15 soldiers there is one captain, then the number of captains in the group is
(a)70
(b)75
(c)80
(d)82
Answer
Answer (as printed): B
Explanation
Let the number of captains in the group be $x$. Then, number of soldiers $=15 x$. $$\therefore \quad x+15 x=1200 \Leftrightarrow 16 x=1200 \Leftrightarrow x=75 .$$
Explanation as extracted from the printed page; notation may be imperfect.