a bank pays 10 percent per annum on savings accounts. Interest is credit quarterly on march 31, June 30, September, and December 31, based on the minimum quarterly  balance. If a person opens an account with a deposit of 200 on January 1 and withdraws 100 on august 8, how much interest is earned in the first year ? คำตอบในหนังสือได้ 15.70 แต่เจ้าของกระทู้คิดได้ไม่ตรง