total sale are
jan= 20000, feb= 22000 march= 24000 apr= 26000 may 28000 june=30000
cash bal on 1st jan was 10000 a new machine is to be installed at rs.30000 on credit to be repaid by 2 equal installment in march n April .
sales commission @5% on total sales is to be apid within the month following actual sales rs. 10000 being the amt of 2nd call may be received in march