Given: Two unbiased dice are rolled together and the sum of the numbers of these two dice will be 7 Concept Used: Probably of an event = Desire event/ Total possible number of events Calculation: On rolling a single unbiased dice we can get 6 possible results On rolling two unbiased dice we can get 62 = 36 possible results Total number of events = 36 Now we can get the sum 7 when two numbers are in such form (6 + 1), (5 + 2), (4 + 3), (3 + 4), (2 + 5) and (1 + 6) i.e. in 6 way The required probability is 6/36 ⇒ 1/6 ∴ The probability of getting the sum of numbers of two dies is 7 is 1/6 Probability of any event must be neither greater than one nor negative.