Over the past 20 years, an economy's total output has grown from 1000 to 1300, its capital

Question:

Over the past 20 years, an economy's total output has grown from 1000 to 1300, its capital stock has risen from 2500 to 3250, and its labour force has increased from 500 to 575. All measurements are in real terms. Calculate the contributions to economic growth of growth in capital, labour, and productivity
a. assuming that aK = 0.3 and aN = 0.7;
b. assuming that aK = 0.5 and aN = 0.5.