Question

Find the L.C.M. of the following numbers.

$0.48,6.4$ and $0.256$

• A. L.C.M. $=$ $19.2$ and H.C.F. $=$ $0.032$
• B. L.C.M. $=$ $6.4$and H.C.F. $=$ $0.48$
  
• C. L.C.M. $=$ $20.2$ and H.C.F. $=$ $1.5$
  
• D. L.C.M. $=$ $12.9$ and H.C.F. $=$ $0.25$
  

Answer 1

The correct option is A L.C.M. $=$ $19.2$ and H.C.F. $=$ $0.032$

Converting each of the decimals into like decimals,we get,
$0.480,6.400,.256$
Now,expressing each of the numbers without the decimals as the products of primes,we get,
$480=2\times 2\times 2\times 2\times 2\times 3\times 5$
$6400=2\times 2\times 2\times 2\times 2\times 2\times 2\times 2\times 5\times 5$
$256=2\times 2\times 2\times 2\times 2\times 2\times 2\times 2$
$\therefore$ H.C.F of $0.480,6.400,.256$
$=2\times 2\times 2\times 2\times 2=32$
$\therefore$ H.C.F of $0.48,6.4,0.256=0.032$
$\therefore$ L.C.M of $0.480,6.400,.256=2\times 2\times 2\times 2\times 2\times 2\times 2\times 2\times 3\times 5\times 5=19200$
$\therefore$ L.C.M of $0.48,6.4,0.256=19.2$