Answer:
45
Step-by-step explanation:
45 = 3*3*5
180 = 2*2*3*3*5 <---- so the other number had to contain a factor of 2*2 or 4
also, let the other number has to be of the form 3k and it must contain a factor of 4, how about 12 ?
check: lcf of 12 and 45 is 3,
the lcm of 12 and 45 is ...
12 = 2*2*3
45 = 3*3*5
so we need: 2*2*3*3*5 = 180