In September, Larson Inc. sold 40,000 units of its only product for $240,000, and incurred a total cost of $225,000, of which $25,000 was fixed costs. The flexible budget for September showed total sales of $300,000. Among variances of the period were: total variable cost flexible-budget variance, $8,000U; total flexible-budget variance, $63,000U; and, sales volume variance, in terms of contribution margin, $27,000U. The sales volume variance, in terms of operating income, for September (to the nearest dollar) was: