Given that LCM of positive integer m and n is 120, and m:n=3:4 and we need to find what is the greatest common factor(GCF) of m and n\(\frac{m}{n}\) = \(\frac{3}{4}\) = \(\frac{3x}{4x}\)
where x was a common factor in m and n which got cancelled out. (x is also the GCF which we are looking for)
=> m = 3x and n = 4x
=> LCM(m,n) = x * 3 * 4 (As x was the common factor and 3 and 4 are the non-common factors) = 12x = 120 (given)
=> x = \(\frac{120}{12}\) = 10
=> GCF(x,y) = 10
So ,
Answer will be DHope it helps!
To learn more about LCM and GCD watch the following videos