You are given a math word problem and you are supposed to make use of mathematical concepts like probability, combinatorics, linear equations, sequences/series, or simple operators like addition, subtraction, division, or multiplication to answer the given question. Choose the best option from the 5 given options and report that option.

Question: There are six cards in which it has two king cards. all cards are turned down and two cards are opened what is the possibility to get two kings.

Option A: 1/15

Option B: 2/15

Option C: 3/15

Option D: 4/15

Option E: 6/15
Option A

Question: If each of 4 digit code is formed of integers from 1 to 50, inclusively, and each of the digits are different, how many possible codes are there?

Option A: 5527200

Option B: 5586300

Option C: 5598600

Option D: 5547800

Option E: 2569800
Option A

Question: If a boat is rowed downstream for 600 km in 20 hours and upstream for 48 km in 4 hours, what is the speed of the boat and the river?

Option A: 21 , 21

Option B: 9 , 21

Option C: 21 , 9

Option D: 9 , 9

Option E: 20 , 8
Option C