Can you find the odd number in the following?

2716, 4135, 5321 and 7145

Can you think of a smallest +ve number such that if we shuffle the digits of the number, the new number becomes double the original number?

Without looking at a calendar, within a minute name, a boy's name using 5 consecutive 1st letters of 5 consecutive months

I am weightless, but you can see me. Put me in a bucket, and I'll make it lighter. What am I?

What is common among 11, 69, and 88?

Can you replace the question mark with the correct number?

Can you count the number of matches in the picture below ?

What number does the below three word/phrase identify and why?
1. Deck
2. Year
3. Singing in the Rain

13 decks of cards have been mixed. What is the minimum number of cards that must be taken out from the above-mixed cards to guarantee at least one 'four of a kind?

Place a mathematical symbol between the numerals 5 and 9 in such a way that the resulting number is greater than 5 but smaller than 9.