The solution for this problem is get first the total sales, credit sales and receivables turnover.
187,000 / 0.086 = $2,174,418 this is your total sales
2,174,418 x 60% = $1,304,651 is your credit sales
1,304,651 / 126,370 = 10.32 times is the Receivables turnover
365 / 10.32 = 35.37 days is the day's sales in receivables