In a certain school, the ratio of boys to girls is 5 to 17. If there are 72 more girls than boys, how many boys are there?  Choose the correct option:
A) 27 B) 36 C) 45 D) 72 E) 108
The ratio of b to G is 5:13 and the other data point is G are more than boys by 72...   Looking at the ratio we can say that the 12(17-5) extra parts caused this diff of 72. so 1 part corresponds to 72/8= 
<gadget id="calculator">72/8</gadget>
<output>9</output>
9 and so   5 parts correspond to 12*9= 
<gadget id="calculator">12*9</gadget>
<output>108</output>
108.   108
<result>E</result>
In a certain school, the ratio of boys to girls is 5 to 17. If there are 72 more girls than boys, how many boys are there?