document.write( "Question 723929: In a typical group of 1000 workers from each of the boatbuilding, iron foundry, and amusement park/arcade industries, there were 30 more injuries in iron foundries (I) than in amusement parks/arcades (A). There were 12 more injuries in amusement parks/arcades than in boatbuildings (B). Among these workers, there were 387 nonfatal occupational injuries. How many injuries took place in each industry?\r
\n" ); document.write( "\n" ); document.write( "I'm guessing (keyword being guessing) that:
\n" ); document.write( "Data:1000 workers, I had 30 more than A and A had 12 more than B and the total is 387.
\n" ); document.write( "Variable: A= amusement parks/arcades, B= boatbuildings, I= iron foundry
\n" ); document.write( "Plan: B+(B+A)+(B+I)= 387
\n" ); document.write( "Equation: B+(B+12)+(B+30)=387
\n" ); document.write( " 3B+42 = 387
\n" ); document.write( " -42 -42
\n" ); document.write( " 3B = 345
\n" ); document.write( " 3B/3 345/3
\n" ); document.write( " B = 115
\n" ); document.write( "Solution: A= 127, B= 115, and I= 145
\n" ); document.write( "Am I right?
\n" ); document.write( "

Algebra.Com's Answer #443474 by MathLover1(20850)\"\" \"About 
You can put this solution on YOUR website!

\n" ); document.write( "there were \"387\" nonfatal occupational injuries\r
\n" ); document.write( "\n" ); document.write( "let the boat-building injuries be \"B\",amusement park/arcade injuries be \"A\", and iron foundry injuries be \"I\"\r
\n" ); document.write( "\n" ); document.write( "given:\r
\n" ); document.write( "\n" ); document.write( "\"B%2BA%2BI=387\"\r
\n" ); document.write( "\n" ); document.write( "\"A=B%2B12\"\r
\n" ); document.write( "\n" ); document.write( "\"I=A%2B30\"...substitute \"A\" ...=> \"I=B%2B12%2B30\"...=> \"I=B%2B42\"\r
\n" ); document.write( "\n" ); document.write( "\"B%2BA%2BI=387\"...plug in all values\r
\n" ); document.write( "\n" ); document.write( "\"B%2B%28B%2B12%29%2B%28B%2B42%29=387\"...solve for \"B\"\r
\n" ); document.write( "\n" ); document.write( "\"3B%2B12%2B42=387\"\r
\n" ); document.write( "\n" ); document.write( "\"3B%2B54=387\"\r
\n" ); document.write( "\n" ); document.write( "\"3B=387-54\"\r
\n" ); document.write( "\n" ); document.write( "\"3B=333\"\r
\n" ); document.write( "\n" ); document.write( "\"B=333%2F3\"\r
\n" ); document.write( "\n" ); document.write( "\"highlight%28B=111%29\"\r
\n" ); document.write( "\n" ); document.write( "now find \"A\" and \"I\"\r
\n" ); document.write( "\n" ); document.write( "\"A=B%2B12\"\r
\n" ); document.write( "\n" ); document.write( "\"A=111%2B12\"\r
\n" ); document.write( "\n" ); document.write( "\"highlight%28A=123%29\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"I=B%2B42\"\r
\n" ); document.write( "\n" ); document.write( "\"I=111%2B42\"\r
\n" ); document.write( "\n" ); document.write( "\"highlight%28I=153%29\"\r
\n" ); document.write( "\n" ); document.write( "check their sum:\r
\n" ); document.write( "\n" ); document.write( "\"B%2BA%2BI=387\"\r
\n" ); document.write( "\n" ); document.write( "\"111%2B123%2B153=387\"\r
\n" ); document.write( "\n" ); document.write( "\"387=387\"\r
\n" ); document.write( "\n" ); document.write( "check your solution: A= 127, B= 115, and I= 145
\n" ); document.write( "Am I right?\r
\n" ); document.write( "\n" ); document.write( "your equation: \"B%2B%28B%2B12%29%2B%28B%2B30%29=387\" ...you put \"I=%28B%2B30%29\", but it is given that \"I\" had \"30\" more than \"A\", or \"I=A%2B30\"\r
\n" ); document.write( "\n" ); document.write( "so, you need to put
\n" ); document.write( "
\n" ); document.write( "\"B%2BA%2B%28A%2B30%29=387\"\r
\n" ); document.write( "\n" ); document.write( "since also given that \"A\" had \"12\" more than \"B\", we know that \"A=B%2B12\" and we go back to \"I\" and substitute \"A\" \r
\n" ); document.write( "\n" ); document.write( "\"I=A%2B30\"...=>...\"I=B%2B12%2B30=B%2B42\"\r
\n" ); document.write( "\n" ); document.write( "now, plug it in equation
\n" ); document.write( "\"B%2B%28B%2B12%29%2B%28B%2B42%29=387\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "
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