There are different ways to calculate this question, but I will explain you easiest way
Daily sales 150 units @ price $300 = $45,000 per day 60% of customers pay due amount within 10 days of discount period $45,000 per day * 10 = $450,000* 60% = $270,000 while the rest of other customers are taking 30 days to pay due amount 45,000 per day * 30 days = 13,50,000*40% = $540,000
Total accounts receivable is here 270,000+540,000 = $810,000 (D)
(OR)
You can also solve this question with number of outstanding days or sales days multiplied by daily sales amount.
In first scenario 60% customers will pay within 10 days 0.60*10 = 6
While the remaining 40% customers will pay within 30 days 0.40*30=12
Total number of days taken by customers is 6+12 = 18
Daily sales units 150*@ price 300 = $45,000 per day sales amount
To get accounts receivable 18*45,000 = $810,000 option (D)
Thanks & Regards
Sumair Shaik
Accountant
United Arab emirates