The answer is 47 because 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47
2 * 7 = 14 (the number of tiles for each row) 23 - 14 = 9 (the number of tiles subtracted from how many tiles that are taken away) 9 tiles are in the seventh row.
Urn 1 = 4 green balls and 6 blue balls, a total of 10 balls
Urn 2 = 6 green balls and 2 blue balls, a total of 8 balls.
Probability of blue balls:
Urn 1 : P = 6/10
Urn 2 : P = 2/8
Probability that both balls are blue:
6/10 * 2/8 = 6*2 / 10*8 = 12/80 = 6/40 = 3/20
Answer is B. 3/20
I don’t really know….but nice computer :)