Answer:
Step-by-step explanation:
Given four tiles with numbers:
1, 4, 5 and 8
Tile chosen once and then replaced, after that another tile chosen:
All possibilities are:
{(1, 1) ,(1, 4) ,(1, 5) ,(1, 8)
(4, 1) ,(4, 4) ,(4, 5) ,(4, 8)
(5, 1) ,(5, 4) ,(5, 5) ,(5, 8)
(8, 1) ,(8, 4) ,(8, 5) ,(8, 8) }
Total number of possibilities = 16
When the sum is greater than 7, the possibilities are:
{(1, 8)
(4, 4) ,(4, 5) ,(4, 8)
(5, 4) ,(5, 5) ,(5, 8)
(8, 1) ,(8, 4) ,(8, 5) ,(8, 8) }
Number of favorable cases = 11
Formula for probability of an event E is:
Hence, the required probability is: