The gcf of two numbers is 3 and their lcm is 180. If one of the numbers is 45 then find the second number.
let the two numbers be x and y
xy = 3*180 = 540 <----- a property of HCF and LCM
suppose x = 45, then y = 540/45 = 12
check:
12 = 2*2*3
45 = 3*3*5
HCF = 3, LCM = 2*2*3*3*5 = 180