Expert Answer:
Since the numbers are in the ratio 3:4 then let the numbers be 3x and 4x.
Thus the H.C.F. of the two numbers = x.
But the H.C.F is given as 4.
So, x = 4.
So, the numbers are,I
3x = 3 x 4 =12
And
4x = 4 x 4 = 16
We know,
H.C.F x L.C.M = Product of the two numbers
4 x L.C.M = 12 x 16
L.C.M = 48
Thus, the L.C.M of 12 and 16 , 48