math word question below

Question

the percentage of electricity generated from natural gas was 27% in 2010 and has increased by about 0.8 % point per year. the % of electricity generated from coal was 48% in 2010 and has decreased by about 0.9 point per year. predict when the % of electricity generated from natural gas will be equal to that from coal. what is the percentage?

Answer 1

.27 + .008years = .48 - .009years      Subtract .27 from both sides.      .008years = .21 - .009years

 

Add .009 years to both sides.        .017years = .21   Divide both sides by .017.      years = 12.35294118

 

2010 + 12 = 2022 (year they will be equal)      .27 + .008(12.35294118) = 36.8823529% = 37% (rounded)