Shown below are the quantities of a commodity demanded by three individuals  A, B & C at different prices in a market.
At price Rs. 10, demand of A = 60, B = 59, C = 62
At price Rs. 20, demand of A = 45, B = 49, C = 49
At price Rs.30, demand of A = 30, B = 39, C = 36
At price Rs.40, demand of A = 15, B = 29, C = 23
What will be the market demand at price of Rs. 20 and 40 respectively? (Assume market consists of only these three consumers)

143, 67

Market demand refers to the sum total of all the individual demand curves pertaining in the market. Demands of A, B and C at price 20 = 45+ 49+49 = 143 Demands of A, B and C at price 40 = 15+ 29+ 23 = 67