Test: Number Play - 1 - Class 6 MCQ

To find the missing number, we can start by adding the given numbers and then subtracting this sum from 38,800:

• Sum of the given numbers: 25,000 + 13,000 + 400 + 400 = 38,800
• The sum of the given numbers is already 38,800.

This means the missing number is 0. However, since 0 is not listed as an option, it seems there might be an issue with the problem or options provided.

A 12-hour clock displays time using the hours 1 through 12, with two cycles for AM and PM. In this format, any time beyond 12:59 would require adjustment.

Let's analyze the options:

• A: 4:44 – This is a valid time on a 12-hour clock (4:44 AM or PM).
• B: 10:10 – This is a valid time on a 12-hour clock (10:10 AM or PM).
• C: 13:13 – This is NOT a valid time on a 12-hour clock, because 13:13 corresponds to 1:13 PM on a 12-hour clock, and times on a 12-hour clock range only from 1 to 12 for the hour.
• D: 12:12 – This is a valid time on a 12-hour clock (12:12 AM or PM).

Therefore, the correct answer is C: 13:13.

The Collatz Conjecture operates under the following rules:

• If the number is even, divide it by 2.
• If the number is odd, multiply it by 3 and add 1.

Starting with the number 12:

• 12 is even, so divide it by 2: 12 ÷ 2 = 6
• 6 is even, so divide it by 2: 6 ÷ 2 = 3

The next number after 6 is 3.

Thus, the correct answer is A: 3.

By definition, a 5-digit number contains exactly 5 digits. This range includes numbers from 10,000 to 99,999, all of which have five digits.

Therefore, the correct answer is 5.

The 2-digit numbers between 10 and 99 start at 10 and end at 99. To find how many 2-digit numbers are in this range, we subtract the smallest 2-digit number (10) from the largest (99) and then add 1:

99 − 10 + 1 = 90

So, there are 90 two-digit numbers between 10 and 99.

Therefore, the correct answer is C: 90.

The reverse of 1234 is obtained by arranging its digits from right to left, resulting in 4321.

• A palindrome reads the same forwards and backwards.

• C: 12/02/2021 → 12022021 → same forwards and backwards 

• A and B are not palindromes.
  So, the correct answer is C.

Whole numbers from 0 to 9 are all 1-digit numbers:
→ {0, 1, 2, 3, 4, 5, 6, 7, 8, 9} = 10 numbers

If the question had asked about natural numbers, the correct answer would have been 9 (1 to 9 only).

Let's find the fourth number in the Collatz sequence starting from 21.

Steps:

1. 21 is odd, so multiply by 3 and add 1:
   21 × 3 + 1 = 64
2. 64 is even, so divide by 2:
   64 ÷ 2 = 32
3. 32 is even, so divide by 2:
   32 ÷ 2 = 16
4. 16 is even, so divide by 2:
   16 ÷ 2 = 8

Sequence:

The sequence starting from 21 is: 21 → 64 → 32 → 16

The fourth number in the sequence is 16.

• 27 is divisible by 3

• 39 is divisible by 3 and 13

• 49 is divisible by 7

• 29 is divisible only by 1 and itself → it’s a prime number