Making the same number of decimal places ,the given numbers are `0.63, 1.05` and `2.10`.
Without decimal places ,these numbers are `63, 105` and `210`.
Now, H.C.F. of `.63, 1.05`and `210` is `21`.
:.H.C.F of `.63, 1.05` and `2.1` is `0.21`.
L.C.M. of `63, `05` & `210` is `630`.
:.L.C.M of `63, 1.05` and `2.1` is `6.30`.

Converting  each of the given fraction into decimal form, we get :

`5/8 = 0.625, 7/12 = 0.5833, 13/16`

` = 0.8125, 16/29 = 0.5517 & 3/4 = 0.75`.
 
 Now `0.5517 < 0.5833 < 0.625 <0.75 < 0.8125`
 
 :. `16/29 < 7/12 <5/8 <3/4 < 13/16`.

(i) `0.6 = 6/9 = 2/3. `      

(ii) ` 0.37 = 37/99`.   

(iii) ` 0.053 = 53/999`.

(iv) `3.142857 = 3+ 0.142857 `

   `= 3 + (142857)/(999999) `

   `= 3 (142857)/(999999)`.

(i) ` 0.17 = (17-1)/90 = 16/90 = 8/45`.

 (ii) ` 0.1254 = (1254-12)/(9900)`

   ` = (1242)/(9900) = 69/(550)`.

 (iii) ` 2.536 = 2 + 0.536 = 2+ (536 - 53)/900`

   ` = 2 + 483/900 = 2 + 161/300 = 2 (161)/300`.