Question 1: 5/8=0.625=62.5% 13/22=about 0.59(repeats 09)=9%
22/30=about 0.73(repeats 3)=73% 12/25=0.45=45%
Store 3 had the greatest percentage of smart phones.
Question 2: 0.775/7.75%=0.775/0.0775=10
For mobile phone 3, it uses o.775 hour of battery life if 7.75% of battery is used.
1 electron has a mass of 9.1 X 10-31 kg. How many electrons n does it take to make 1 kg?
(1 e)/(9.1 X 10-31 kg) = n/(1 kg)
So, n = 1.10 X 1030 electrons
Each electron has a charge of 1.6 X 10-19 C, where C stands for Coulombs. So, the n electrons have a charge of q = ne = (1.10 X 1030 electrons) X (1.6 X 10-19 C/electron) = 1.76 X 1011 C.
