How many significant figures are in the following numbers a

How many significant figures are in the following numbers? (a) 78.9 plusminus 0.2 (b) 3.788 times 10^9 (c) 2.46 times 10^-6 (d) 0.005 3

Solution

(a) 78.9+/- 0.2   - has significant figures

(b) 3.788e+9 -- has 4 significant figures

(c) 2.46e-6     -- has 3 significant figures

(d) 0.0053     -- has 2 significant figures