To find the time in which all the bells ring together, we need to find the LCM of 36,40,48.
Prime factorization of 36=2×2×3×3
Prime factorization of 40=2×2×2×5
Prime factorization of 48=2×2×2×2×3
Hence, LCM of 36,40,48=2×2×2×2×3×3×5=720 seconds.
720seconds=
60
720
minutes=12minutes
Hence, all the bells will ring together after 12 mi