Below is an instruction that describes a task. Write a response that appropriately completes the request in Swahili. Please answer in Swahili.

### Instruction:
A library has 7 rectangular tables and the remaining tables will be square tables. A rectangular table seats 10 pupils while a square table seats 4 pupils. How many square tables are needed so that 90 pupils can read at the same time?

### Response:
 Meza za umbo la pembetatu zinaketi wanafunzi 7*10=<<7*10=70>>70.
Meza za umbo la mraba zitaketi wanafunzi 90-70=<<90-70=20>>20.
Maktaba inahitaji meza 20/4=<<20/4=5>>5 za umbo la mraba.