3 x 0.3 x 0.03 x 0.003 x 30 =?

Here to say which fraction is greater from the given options, the fraction with greater numerator with same denominator or smaller denominator with same numerator.

To find the greater fraction, among the given options, make the denominators same for the options by finding the LCM of all the denominators.

7/12, 9/16, 13/20, 32/80

Now, LCM of 12, 16, 20, 80 = 240.

Then,

140/240, 135/240, 156/240, 96/240

Here 

$$\begin{gathered} 156240 > 140240 > 135240 > 96240 \\ => 1320 > 712 > 916 > 3280 \end{gathered}$$

Hence, largest fraction = 13/20.

Expressing 3/8 as a decimal fraction:

We can convert 3/8 into a decimal fraction by just dividing 3 by 8 or making 3 into 8 parts.

Then, it is 3/8 = 0.375 as a decimal fraction.

Other Method::

3/8 as a Decimal :

In this we should convert the denominator into 10, 100, 1000, 10000, 100000,... to make it simple.

Now to make 8 into 1000, we multiply numerator and denominator with 125

=> (3 x 125)/(8 x 125) = 375/1000 = 0.375.

1/8 to convert into decimal,

Find an equivalent fraction with a denominator of a power of 10.

In this case, we will use 1000.

18 x 125125 = 1251000

This can now be written as a decimal with 3 decimal places (because we have thousandths.

i.e, 0.125

Hence, 18 as a decimal = 0.125

125 over 1000 in Simplest Form means 1251000 in its simple fraction form.

Now, to get the simplest form of 125/1000, find the HCF or GCD of both numerator and denominator i.e, 125 and 1000.

HCF of 125, 1000 = 125

Then, divide both numerator and denominator by 125

i.e, 1251251000125 = 18

Hence, 18 is the simplest form of 125 over 1000.