What will be the best approach to finding all the prime numbers less than 75 that leave an odd reminder when we divide them with 5?

Only one colour, but not one size,
Stuck at the bottom, yet easily flies.
Present in sun, but not in rain,
Doing no harm, and feeling no pain.
What is it?

Count the number of balls in picture below:

Pronounced as 1 letter, And written with 3, 2 letters there are, and 2 only in me. I’m double, I’m single, I’m black blue and grey, I’m read from both ends, and the same either way. What am I?

You need to climb ten stairs. At every stair, you can either take one step up or you can jump two steps up.

In how many different ways you can climb 10 stairs?

Is the statement valid that it does not matter how much older a sibling is, eventually the younger one will be half as old as the older one?

Make eight squares by moving only two matchsticks.
Note- Square can be of different sizes.

Can you identify the hidden rebus in the image below?

What is the next number in the series?

15 29 56 108 208 ?

Twenty frogs are sitting on a log floating on the surface of a river. Two of them decide to jump off into the water.

How many frogs are there on the log at this moment?