Interest = Pin = principal * interest rate * number of years
Let interest rate be i, then
600*i*2+150*i*4=90
1200i+600i = 90
i=90/(1200+600)=90/1800=1/20=0.05 or 5%
Hydrogen is around 0.000053% and Helium is around <span>0.000524%</span>
66/128 * 100
51.56 % if rounding to the nearest hundredth.
51.6 % if rounding to the nearest tenth.
52 % if rounding to the nearest whole number.