Answer:
B
Step-by-step explanation:
In a triangle, the sum of any two sides must be bigger than the third.
For the first one, 10+20=30 is not greater than 30, so this is not correct.
For B, 122+137 = 259 > 257, 257+137>122 , and 257 + 122 > 137. This works
For C, 8.6 + 2.7 = 11.3 < 12.2, so this does not work
For D, 1/6 + 1/5 = 5/(6*5) + 6/(6*5) = 5/30 + 6/30 = 11/30 < 1/2 = 15/30, so this does not work
