Question

Evan's mother's birthday is in January, but he forgot the date. To help him, his father gave him some clues. Help Evan find his mother's birth date.
1. It is a multiple of 7.
2. It is after 15.
4. In Roman numerals, this number is written using 2 different symbols.

• A. 18
• B. 21
• C. 24
• D. 27

Answer 1

The correct option is B 21

First, let's look at the calender for the month of January:


Now, let's look at all the clues one by one:

1. It is a multiple of 7. Here multiples of 7 are: 7, 14, 21 and 28

2. It is after 15 January.
Numbers that are greater than 15 in this list are: 21 and 28.

The third clue says it is written using 2 different symbols in Roman numerals.

Let's write the given numbers in Roman numerals:

21: XXI
28: XXVIII

21 is written using 2 different symbols and 28 is written using 3 different symbols.
Hence, Evan's mother's birthday is on 21 January.