Which number should replace the question mark?

Can you find out the smallest number that can be conveyed as the sum of three squares in three unique ways?

What number comes next in the series?

5 15 5 18 5 24 14 20 _

What work can one never finish?

_ _ _ IE _ _
_ _ _ IE _
_ _ IE _ _
_ _ IE _
_ _ _ _ IE

Like you see, some letters have gone missing from these words that contain the IE pair at some or the other place. The letters that will be used to fill the blanks are given below. Use them and form meaningful words. Can you do that?

A, C, D, F, H, K, L, M, N, N, O, R, R, S, S, S, T, T, Y and Y.

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

There are three boxes of different sizes with three cupcakes inside each of the boxes in Christina's kitchen. At night her daughter wakes up and goes to the kitchen. She opens a box and eats all three cakes.

But in the morning Christina finds out that each box still had three cupcakes. How?

Can you find the missing piece of the Porsche?

Name a key which is hardest to turn.

Find the next number in the sequence

1, 2, 6, 21, 88, __?