Laura borrowed $2400 from her parents to pay for her college education. If she pays back 2½ percent of this amount quarterly, and she has paid back $420, for how many months has she been paying back for her loan?
A. 6; B 7; C. 21: D. 24; E. 28.
The answer is C.
请问NN, 这题该怎么计算。 非常感谢 |