Concept: The question tests on Per cent and Interest
Solution:
California in 1980 = 0.33 of 1.2 * 10^9
California in 1990 = 0.33 of 1.6 * 10^9
From 1980 to 1990 California increased its production by 0.33 ( 1.6 * 1.4) * 10^9
= 33 * 4 106 = 132 Million
Oregon in 1980 = 0.17 of 1.2 * 10^9
Oregon in 1990 = 0.17 of 1.6 * 10^9
From 1980 to 1990 Oregon increased its production by 0.17 ( 1.6 * 1.4) * 10^9
= 17 * 4 10^6= 68 Million
The difference in increase = 132 - 68 = 64 million
Option B