Question
( 21=7 times 3 )
19. ( (3) because quad 21=1 ). ( quad 66=3 times 2 times 11 )
( 36=3 times 3 times 2 times 2 ) and
( therefore angle C M ) of 21,36 and 66 ( =3 times 3 times 2 times 2 times 7 times 11 )
Hence, required perfect square number ( =3 times 3 times 2 times 2 times 7 times 7 times 11 times 11 )
( =9 times 4 times 49 times 121 )
( =36 times 49 times 121=213444 )

19. The least perfect square which is divisible by each of 21, 36 and 66 is (1) 214344 (2) 214434 (3) 213444 (4) 231444
Solution
