Questions

In each circle,lower number equals the product of the top two numbers, subtracting 3 for the left hand circle, 4 for the middle, and 5 for the right hand circle.

You will get the answer in the riddle itself, if you read the riddle carefully.

The riddle says "A cowboy arrives in town on Friday." So Friday is the name of the horse on which he comes. Hence, the only possibility is he arrives on the horse friday on Tuesday, stays for 3 days and leaves on the same horse on Friday. 

UNIA - Universal Negro Improvement Association.

It is primarily in the United States, organization founded by Marcus Garvey, dedicated to racial pride, economic self-sufficiency, and the formation of an independent black nation in Africa.

Qualm means feeling confused, uneasiness, very doubtful and being in worry.

Hence, among the given options, Qualm is the opposite of Confidence.

We know that, in solids all the particles are packed together and hence sound can travel from one to one very fast.

Hence, speed of sound is maximum in solids and decreses from solids to liquids and liquids to gases. Sound can't travel through vaccum.