document.write( "Question 862659: Together, Grandma and Grandpa are 140 years old. How old is Grandma if Grandpa was twice as old as Grandma was when Grandpa was as old as Grandma is now. \n" ); document.write( "
Algebra.Com's Answer #854473 by MathTherapy(10839)\"\" \"About 
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document.write( "Together, Grandma and Grandpa are 140 years old.  How old is Grandma if Grandpa was twice as old as Grandma\r\n" );
document.write( "was when Grandpa was as old as Grandma is now.\r\n" );
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document.write( "Let Grandpa's and Grandma's ages, be P, and M, respectively\r\n" );
document.write( "SInce their ages sum to 140, we get: P + M = 140___M = 140 - P ---- eq (i)\r\n" );
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document.write( "\"Grandpa was as old as Grandma is now,\" clearly signifies that Grandpa is older than Grandma, which means that\r\n" );
document.write( "the difference in their ages is: P - M\r\n" );
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document.write( "When was Grandpa as old as Grandma is now?\r\n" );
document.write( "This is the SAME as the difference in their ages, or P - M = P - (140 - P) = P - 140 + P = \"2P - 140\" years ago\r\n" );
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document.write( "So, when Grandpa was as old as Grandma is now, Grandpa was: M, or \"140 - P\" years-old\r\n" );
document.write( "And, when Grandpa was as old as Grandma is now, Grandma was: 140 - P - (2P - 140) = 140 - P - 2P + 140 = - 3P + 280\r\n" );
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document.write( "Finally, since \"Grandpa was twice as old as Grandma was when Grandpa was as old as Grandma is now,\"\r\n" );
document.write( "we have:        140 - P = 2(- 3P + 280)\r\n" );
document.write( "                       140 - P = - 6p + 560\r\n" );
document.write( "                     - P + 6P = 560 - 140\r\n" );
document.write( "                              5P = 420\r\n" );
document.write( "Grandpa's age, or \"P+=+420%2F5+=+84\"\r\n" );
document.write( "Therefore, Grandma is 140 - P = 140 - 84 = 56
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