求助~~数学题???谢谢

l2008v

1.If the number of square units in the area of circle C is twice the number of linear units in the circumference of C,what is the number of square units in the area?A 4 B 8 C 4π D 8π E16π (不理解是什么意思)

2.Four cups of milk are to be poured into a 2-cup bottle and a 4-cup bottle.If each bottle is to be filled to the same fraction of its capacity,how many cups of milk should be poured into the 4-cup bottle?

A2/3 B7/3 C2/5 D8/3 E3

3.A three-digit code for certain logs uses the digits 0,1,2,3,4,5,6,7,8,9 according to the following constraints.The first digit cannot be 0 or 1,the second digit must be 0 or 1,and the second and the third digits cannot both be 0 in the same code.How many different codes are possible?

A144 B152 C160 D168 E176(能讲一下这种排列组合的思路吗？)

会做就帮忙做一下吧！！！非常感谢1E 2D 3B

[此贴子已经被作者于2009/7/23 19:35:09编辑过]