Question

( quad S=S times 1=5 )
( 1 S=5 times 3=5^{prime} times 3^{prime} )
( 20=2 times 2 times 5=2^{2} times 5^{prime} )
( L cdot C cdot M==2^{2} times 3 times 5=60 )
( 1-1 cdot C cdot F=5^{prime}=5 )

# 21. Find the ratio between the LCM and HCF of 5,15, 20

Solution