What is next number in the pattern below:

131 517 192 123 ?

At my favorite fruit stand,
an orange costs 18,
a pineapple costs 27,
and a grape costs 15.
Using the same logic, can you tell how much a mango costs?

Quickly Solve this riddle

7 - 4 + 3 * 0 + 1 = ?

Count the number of squares in the picture below.

Can you find the key in the picture below?

If it took eight men ten hours to build a wall, how long would it take four men to build it?

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

PS: You may start the number from 0.

Can you find the missing piece of the Porsche?

Andrew’s doctor gives him three pills and tells him to take one every half hour. How much time will have passed by the time Andrew’s taken all three pills?

I go up and I go down.
I go up towards the beautiful sky and down toward the green ground.
I am present tense.
I am past tense too
Children love me.

Who Am I?