What is the smallest natural number which is divisible by 25 and 55?

Given: 

Given numbers are 25 and 55.

To find: 

Here, we have to find the smallest natural number which is divisible by both 25 and 55.

Solution:

The smallest number which is divisible by any two numbers is their LCM.

Now,

Writing the numbers as a product of their prime factors:

Prime factorisation of 25:

• $25=5\times5=5^2$

Prime factorisation of 55:

• $55=5\times11=5^1\times11^1$

Multiplying the highest power of each prime number:

• $5^2\times11^1=25\times11=275$

LCM(25, 55) $=$ 275

So, the smallest number which is divisible by both 25 and 55 is 275.