Find the following values without a calculator.
For 3 and 5,
- what is the first common multiple?
- what is the second common multiple?
- what is the fourth common multiple?
(a)
Multiples of 3: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36, 39, 42, 45, 48
Multiples of 5: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50
First common multiple = 15
(a)
15 x 2 = 30
Second common multiple = 30
(a)
15 x 4 = 60
Fourth common multiple = 60
Answer(s): (a) 15; (b) 30; (c) 60