document.write( "Question 252285: How many numbers from 1 to 1 million, inclusive, are NOT perfect squares or perfect cubes?\r
\n" );
document.write( "\n" );
document.write( "a. 998,000 b. 998,830 c. 998,900 d. 998,910 e. 999,000 \n" );
document.write( "
Algebra.Com's Answer #184165 by drk(1908)![]() ![]() ![]() You can put this solution on YOUR website! First lets look at perfect squares: 1^2, 2^2, 3^2, 4^2, . . . , 1000^2 are all perfect squares <= 1 million, inclusive.\r \n" ); document.write( "\n" ); document.write( "Second, let's look at perfect cubes: 1^3, 2^3, 3^3, 4^3, . . . , 100^3 are all perfect cubes less than or equal to 1 million inclusive.\r \n" ); document.write( "\n" ); document.write( "So we have 1100 so far. \r \n" ); document.write( "\n" ); document.write( "But notice that some perfect squares are perfect cubes. That occurs at perfect sixth powers. we have to eliminate this overlap. Perfect sixth powers are: 1^6, 2^6, 3^6, . . . , 10^6 are all perfect sixth powers less than or equal to 1 million inclusive.\r \n" ); document.write( "\n" ); document.write( "So, 1 million - 1100 +10 = 998,910. \n" ); document.write( " |