英语翻译
A child withdraws from his piggy bank 10% of the original sum in the bank.If he must add 90 cnets to bring the amount in the bank back up to the original sum,what was the original sum in the bank?
最好能够翻译一下,不过到现在为止都看着有点混乱..
An apartment building has 5 floors,one of which has only 2 apartments.Each of the other floors has 4 apartments.
比较：
3 times the number of floors in the building
the number of apartments in the building
这个apartment 是什么？一个floor怎么会有2个apartment？