The ratio of boarders to day students at a school was originally 5 to 12. However, after a number of new boarders join the initial 150 boarders, the ratio changed to 1 to 2. If no boarders became day students and vice versa, and no students left the school, how many new boarders joined the school?	Choose the correct choice from the following options:	A) 30	B) 50	C) 70	D) 80	E) 90
Let x be the number of new boarders.   The ratio changed from 5:12 up to 1:2 = 6:12.   150 / (150+x) = 5/6   x = 30   The answer is 30.
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The ratio of boarders to day students at a school was originally 5 to 12. However, after a number of new boarders join the initial 150 boarders, the ratio changed to 1 to 2. If no boarders became day students and vice versa, and no students left the school, how many new boarders joined the school?