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

Find The Next Number in this series.
1, 2, 6, 42, 1806 ?

Place the numbers from 1 to 9 in the circles in a manner that each side of the triangle sums up to 17.

If six children and two dogs were under an umbrella, how come none of them got wet?

When is the top of a mountain similar to a savings account?

A father's child, a mother's child, yet no one's son.

Who am I?

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?

Can you count the number of squares in the given picture?

Can you name any English verb that becomes its past tense by simply rearranging the alphabets ?

What is the next number in the series?

15 29 56 108 208 ?