What does the below image rebus riddle means ?

It walks on 4 when its young, walks on 2 when it's older, and walks on 3 when its very old?

I am sometimes honest
Sometimes dishonest
I can be sweet and also bitter
I can hurt you real bad and
also make u smile and blush ☺️
What am I?

Can you move 2 matchsticks to form four equal sized squares.

In the following series, a set of numbers is progressing with a particular pattern. Can you deduce that pattern and find the missing set?

(2 + 6), (21 + 6), (58 + 6), (119 + 6), ___

What has lots of eyes, but can’t see?

Find out a multi-digit number that if multiplied by the number 9 or any of its multiplications products (i.e. 18, 27, 36, 45,..) will result in the multiplication factor repeated (n) number of times.

I have a hole in my back and legs I lack.
I live where I can’t breathe and I eat without teeth.
What am I?

In a competitive exam, each correct answer could win you 10 points and each wrong answer could lose you 5 points. You sat in the exam and answered all the 20 questions, which were given in the exam.
When you checked the result, you scored 125 marks on the test.

Can you calculate how many answers given by you were wrong?

You have $100 with you and you have to buy 100 balls with it. 100 is the exact figure and you can't go below or above the numbers and you have to use the entire $100. If there is no kind of tax applied how many of each of the following balls will you be able to buy:

Green Balls costing $6
Yellow Balls costing $3
Black Balls costing $0.10

Now, how many of each must you buy to fulfil the condition given?