Question

Using all three methods, find the H.C.F. of $20,25,35$ and $50$.

Answer 1

Finding the H.C.F. of $20,25,35$ and $50$ by using common factor method.

Factors of $20$ are $1,2,4,5,10$ and $20$.

Factors of $25$ are $1,5$ and $25$.

Factors of $35$ are $1,5,7$ and $35$.

Factors of $50$ are $1,2,5,10,25$ and $50$.

Common factors of $20,25,35$ and $50$ are $1$ and $5$.

Hence, the H.C.F. of $20,25,35$ and $50$ is $5$.

Finding the H.C.F. of $20,25,35$ and $50$ by using prime factorisation method.

Prime factorisation of $20=2\times 2\times 5$

Prime factorisation of $25=5\times 5$

Prime factorisation of $35=5\times 7$

Prime factorisation of $50=2\times 5\times 5$

Common prime factor is $5$.

Hence, the H.C.F. of $20,25,35$ and $50$ is $5$.

Finding the H.C.F. of $20,25,35$ and $50$ by using division method.

H.C.F of $20$ and $25$.

Hence, H.C.F of $20$ and $25$ is $5$.

H.C.F of $5$ and $35$.

Hence, H.C.F of $5$ and $35$ is $5$.

H.C.F of $5$ and $50$.

Hence, H.C.F of $5$ and $50$ is $5$.

Hence, the H.C.F. of $20,25,35$ and $50$ is $5$.