JNU SSS 2013 doubt (Question 60)

[E A Ibrahim]

60. The GDP of a country is growing at 5%, its population growth is 2% and its income
elasticity for food is 0.5. We can expect food demand to grow at
(a) 2.0 percent
(b) 2.5 percent
(c) 3.5 percent
(d) 5-0 percent

I don't know how to approach this question. Please help by providing steps to solve the problem.

[kangkan]

icome elasticity of food = %change in demand for food/% change in incomes

0.5= %change in demand for food/5
% change in demand for food= 2.5

:)