e) In January N1, Indiana started a sponsorship program for its individual clients. Each client who sponsors new clients for Indiana within 12 months will get a refund of 10% on their previous purchases. Indiana generated sales of 20 million in N1; 30% from individual clients. Indiana's marketing director estimates that for this kind of sponsorship program, 15% of the clients usually benet from the refund. On 31 December N1, 20,000 have already been refunded to clients according to this sponsorship program