why number 8549176320 is one of a kind?

Decode below three cipher riddles:

26 L of the A
7 D of the W
1000 Y in a M

John was gifted a new Hayabusa. He drove x miles at 55mph. Then he drove x+20 miles at 40mps. He drove his bike for 100 minutes. How much distance did he travel?

Which of the eight images will fill the missing image in the puzzle below?

What does an Island and the letter T have in common?

The following alphametic has only one solution. Can you find it?
ENLIST + SILENT + LISTEN = ANAGRAM

PS: You may start the number from 0.

A mathematician couple was having a Frappuccino in Starbucks sitting opposite to each other. Suddenly the guy noticed the text written on the paper in front of them and exclaimed that it was wrong. The girl denied it and said it is appropriate. Both are correct. What is written on the paper?

In the given figure, you can see that four match sticks are used to form a square. Can you form five squares by using six matches?

In a school, 280 students studied chemistry, 254 students studied physics and 280 students studied biology.

97 students studied chemistry as well as physics, 138 students studied physics as well as biology and 152 students studied chemistry as well as biology.

73 students studied all the three branches.

Can you find out the total number of students?

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