Answer:
6.8
Step-by-step explanation:
143.6/21.2 = 6.7736 rounds to 6.8
All non-zero digits to the left of the decimal are significant. 143.6 and 21.2 both have just 1 sig fig to the right of the decimal, so the answer can only have 1 sig fig to the right of the decimal. You have to round to the nearest tenth, hence .7736 rounds up to .8