Find the LCM of $0.7$, $0.35$, and $1.05$.

To find the LCM of decimals, convert them into fractions or make the number of decimal places equal.
Equating decimal places up to two digits:

* $0.70=\frac{70}{100}$
* $0.35=\frac{35}{100}$
* $1.05=\frac{105}{100}$

Now, find the LCM of the numerators ($70,35,105$) and divide by the common denominator ($100$).

$$\text{LCM}(70,35,105):$$

* $35=5\times 7$
* $70=2\times 5\times 7$
* $105=3\times 5\times 7$

$$\text{LCM}=2\times 3\times 5\times 7=210$$

Now, divide by $100$:

$$\text{Required LCM}=\frac{210}{100}=2.1$$