Question

Write 0.216 as a rational number in lowest terms

Answer 1

Answer:

$=\frac{27}{125}$

Step-by-step explanation:

$0.216$

$\mathrm{Multiply\:and\:divide\:by\:10\:for\:every\:number\:after\:the\:decimal\:point.}$

$\mathrm{There\:are\:}3\mathrm{\:digits\:to\:the\:right\:of\:the\:decimal\:point,\:therefore\:multiply\:and\:divide\:by\:}1000$

$=\frac{0.216\cdot \:1000}{1000}$

$=\frac{216}{1000}$

$216,\:1000$

$\mathrm{The\:GCD\:of\:}a,\:b\mathrm{\:is\:the\:largest\:positive\:number\:that\:divides\:both\:}a\mathrm{\:and\:}b\mathrm{\:without\:a\:remainder}$

$2,\:3\mathrm{\:are\:all\:prime\:numbers,\:therefore\:no\:further\:factorization\:is\:possible}$

$=2\cdot \:2\cdot \:2\cdot \:3\cdot \:3\cdot \:3$

$2,\:5\mathrm{\:are\:all\:prime\:numbers,\:therefore\:no\:further\:factorization\:is\:possible}$

$=2\cdot \:2\cdot \:2\cdot \:5\cdot \:5\cdot \:5$

$\mathrm{The\:prime\:factors\:common\:to\:}216,\:1000\mathrm{\:are\:}$

$=2\cdot \:2\cdot \:2$

$\mathrm{Multiply\:the\:numbers:}\:2\cdot \:2\cdot \:2=8$

$=8$

$=\frac{8\cdot \:27}{8\cdot \:125}$

$\mathrm{Cancel\:the\:common\:factor:}\:8$

$=\frac{27}{125}$

Hence, the correct answer is $=\frac{27}{125}$