Why did China ultimately open up to investment by western businesses by the late 1970s and into the 1980s

Abc factory produces 24,000 units. the cost sheet gives the following information: direct materials rs. 1,20,000direct labour rs. 84,000variable overheads rs. 48,000semi variable overheads rs. 28,000fixed overheads rs. 80,000total cost rs. 3,60,000presently the product is sold at rs. 20 per unit.the management proposes to increase the production by 3,000 units for sales in the foreign market . it is estimated that semi variable overheads will increase by rs. 1,000. but the product will be sold at rs. 14 per unit in the foreign market. however, no additional capital expenditure will be incurredq-1. what is present profit of the company ? q-2. what is proposed profit of the company in new market? q-3.what is suggestion for new makret proposal whether proposal accept or not