Two numbers, such as 4x32, indicate the magnification (4 times) and the size of the front (objective) lens- 32 mm. A bigger lens is usually brighter. Three numbers, such as 6-24x42 or 6x24x42 will indicate a variable power scope- from 6 to 24 power, with a 42mm front lens.
168This is a classic example in which the LCM won't be the amount (24x42). A simple way (not necessarilly the best) is to go from 42,84,126 etc untill 24 fits in. In this case 168 fits into both (24x7) and (42x4).168Solution Method:1. Factor 24: 2*2*2*32. Factor 42: 2*3*73. List the least common factors: 2*2*2*3*7 = 1684. Check: 168/24=7 (no remainder is good)5. Check: 168/42=4 (no remainder is good)======