Let 'R%' be the rate of interest

From the given data,

$$\begin{gathered} 25202400 = 1 + R10041 + R1003 \\ ⇒1 + R100 = 6360 \\ ⇒R = 5 \end{gathered}$$

Hence, the rate of interest R = 5% per annum.

A Clock has 3 hands i.e, an Hour hand, a Minute hand and a Seconds hand.

Breeding and management of bees is called Apiculture.

A beekeeper or apiarist keeps bees in order to collect their honey and other products that the hive produces (including beeswax, propolis, flower pollen, bee pollen, and royal jelly), to pollinate crops, or to produce bees for sale to other beekeepers.

A location where bees are kept is called an 'apiary' or 'bee yard.'

Given A,B,C can complete a work in 15,20 and 30 respectively.

The total work is given by the LCM of 15, 20, 30 i.e, 60.

A's 1 day work = 60/15 = 4 units

B's 1 day work = 60/20 = 3 units

C's 1 day work = 60/30 = 2 units

(A + B + C) worked for 2 days = (4 + 3 + 2) 2 = 18 units

 Let B + C worked for x days = (3 + 2) x = 5x units

C worked for 2 days = 2 x 2 = 4 units

Then, 18 + 5x + 4 = 60

22 + 5x = 60

5x = 38

x = 7.6

Therefore, total number of days taken to complete the work = 2 + 7.6 + 2 = 11.6 = 11 3/5 days.

Donkeys and horses can be breed to make mules and hinnys.

A hinny is a domestic equine hybrid that is the offspring of a male horse, a stallion, and a female donkey, a jenny. It is the reciprocal cross to the more common mule, which is the product of a male donkey, a jack, and a female horse, a mare.

The process of collecting, organizing and analyzing data is called Statistics.

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. 

The Aortic valve - located between the left ventricle and the aorta

The Mitral valve - located between the left atrium and left ventricle

The Tricuspid valve - located between the right atrium and the right ventricle (and) 

The Pulmonary (pulmonic) valve - located between the right ventricle and the pulmonary artery.