Mathematics for IGCSE & O level - Limits Of Accuracy (Section 1 - No. 37)

What is the upper bound of the sum of 29.7 seconds and 31.4 seconds, both to 3 significant figures?

61.05 s

61.1 s

61.15 s

61.2 s

Upper bound of 29.7 is 29.75. Upper bound of 31.4 is 31.45. Upper bound of the sum = 29.75 + 31.45 = 61.2 seconds