Solution:

I am a Postbox

Remove as many letters as possible, still postbox remains the same.

Solution:

888 + 88 + 8 + 8 + 8 = 1000

Solution:

step 3 is wrong

Solution:

It can be down as shown below.

Solution:

30,450 miles.

Explanation:
For each 5 miles driven using this rotation, each tire will lose (2/29000)+(2/21000) of its tread.So, suppose we drive 5*N miles like this. Then, each tire will lose 2*N*((1/29000)+(1/21000)) of its tread. We wish to determine N so that the latter expression gets to be 1, representing all of each tire's tread. That happens when N=6090, which is when 5*N (the total miles driven) is 30,450.

Solution:

Read the question carefully again. New Year do falls after Christmas but that happens if two different years. The question is put up against the year 2050 and thus there will be 51 weeks and 2 days in between them as New Year will appear on 1 January 2050 and Christmas will happen on 25 December 2050.

Solution:

Rhea will open just one present.
Cindy|Y - Y is the 25th alphabet
Duk|E - E is the 5th alphabet
Joh|N - N is the fifteenth alphabet
Rhe|A - A is the first alphabet

Solution:

Hhe hung herself using big Ice slabs , which are now now melted and hence puddle of water.

Solution:

Solution is shown in image below

Solution:

Pages 19, 20, 23, 37, 38, & 42 will also be missing

Solution:

They are matched as shown in the picture below.