陈向东数学里的一道题，请高手指点

mingmings

3、Together ,Andrea and Brian weigh p pounds; Brian weighs 10 pounds more than Andrea. Brian and Andrea's dog,Cubby,weighs p/4 pounds more than Andrea. In terms of p. What's Cubby's weight in pounds?
A  p/2-10   B 3p/4-5   C 3p/2-5   D 5p/4-10   E 5p-5
我觉得题目有问题，我按上面算没有一个答案可以选的，我算的答案是5P/8-25/4
B+A=P
B-A=10
C=5/4A

mingmings

还有一题，题意有点看不懂。
If the value of a piece of property decreases by 10 percent while the tax rate on the property increases by 10 percent, what is the effect on the taxes?
A taxes increase by 10 percent
B taxes increase by 1 percent
C there is no change in taxes
D taxes decrease by 1 percent
E taxes decrease by 1 percent
这里的effect是tax跟什么进行比较？

mingmings

上一题答案选D taxes decrease by 1 percent E 选项是10%,打掉了一个0

mingmings

还有一题
During a sale at an office supply store, for every box of paper clips purchased for 15 cents, a sceond box can be purchased for 4 cents. How many boxes of paper clips did Paul buy if he spent 91 cents on boxes of paper clips?
A 6   B 7   C 8  D 9   E 10
答案选D
a sceond box can be purchased for 4 cent之后的意思是说从第二个盒子开始每盒只卖 4 cents.
按照这样的思路：91=15+4x 接触X=19 再加上花15cent买的那一盒就为20盒

mingmings

会做了，看错了，把多重p/4pounds看成多A的1/4

mingmings

If n is a positive integer and n^2 is divisible by 72 ,then the largest positive integer that must divide n is?  给的答案是B
   A 6 B 12 C 24 D36 E48
怎么做这一题？