Question

A salesman travels to Chicago every 15 days and another salesman travels to Chicago every 24 days. Today, both are in Chicago. After how many days both salesman will be again in Chicago on same day?

• A. 24
• B. 240
• C. 60
• D. 120

Answer 1

The correct option is D 120

The LCM of 15 days and 24 days is the next time both salesman would be again in Chicago.

Let's find the LCM using prime factorizations of 15 and 24 are

15 = 3 × 5
24 = 2 × 2 × 2 × 3

LCM is the product of maximum occurrences of each prime factor in the given numbers.

So LCM(15, 24) = 2 × 2 × 2 × 3 × 5 = 120 days.

So both salesmen will be in Chicago after 120 days.