Convert the following statement scales to RF scale: i) 2cm to 1km, ii) 1cm to 1km

Step 1: Convert the ground distance of 2 km to cm, keeping units consistent.

Formula:
$1~km = 1000~\mathrm{m}$
$1~m = 100~\mathrm{cm}$
$1~km = 1000 \times 100 = 100{,}000~\mathrm{cm}$

Substitute for 2 km:
$2~km = 2 \times 100{,}000~cm = 200{,}000~\mathrm{cm}$

Step 2: Form the representative fraction (RF) scale using same units (cm) for map and ground distances.

Map distance = $1~\mathrm{cm}$
Ground distance = $200{,}000~\mathrm{cm}$

RF scale:
$1~cm : 200{,}000~cm = 1 : 200{,}000$

Final answer:
1:200000