Answer
a) 1.28 km
b) 3.18x$10^{-3}$ mg
c) 8.14x$10^{7}$ dm
d) 3.8 m/s
Work Step by Step
in multiplication and division we follow the least significant figures
in addition and subtraction we follow the most significant figure
a) 7.310km÷5.70km
= 1.2824
= 1.28 km
b) (3.26 x $10^{-3}$ mg) - (7.88 x$10^{-5}$mg)
= 3.1812x$10^{-3}$
=3.18x$10^{-3}$ mg
c) (4.02 x $10^{6}$ dm) + (7.74 x $10^{7}$ dm)
=81420000
=8.14x$10^{7}$ dm
d) (7.8 m - 0.34 m)/(1.15 s + 0.82 s)
= 7.46 m/1.97 s
= 3.78680
= 3.8 m/s
