Find the HCF of 16.5, 0.45 and 15.

Correct option is C

Given:
We need to find the HCF (Highest Common Factor) of the numbers:
16.5
0.45
15
Solution:
Multiply each number by 100 to eliminate decimals:
​$$16.5 \times 100 = 1650 \\ \ \\0.45 \times 100 = 45 \\ \ \\15 \times 100 = 1500$$​​
Factorize each number:
1650 =$$2 \times 3 \times 5^2 \times 11$$​​
4$$5 = 3^2 \times 5$$​​
​$$1500 = 2^2 \times 3 \times 5^3$$​​
The common primes in all three numbers are 3 and 5.
Take the lowest power of each common prime:
​$$3^1$$​ (from 1650 or 1500, since 45 has $$3^2$$​​
​$$5^1$$​ (from 45, since others have higher powers)
HCF = 3$$\times 5 = 15$$​​
Since we multiplied by 100 earlier, now divide the HCF by 100:
HCF = $$\frac{15}{100} = 0.15$$​​