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

### Instruction:
Nico borrows 3 books from the library on Monday.  On Monday, he reads the first book with a total of 20 pages.  On Tuesday, he reads the second book with a total of 12 pages.  On Wednesday, he reads the third book.  If he has read a total of 51 pages from Monday to Wednesday, how many pages did he read on Wednesday?

### Response:
 Nico alikopa vitabu 3, hivyo alisoma jumla ya kurasa 20 + 12 + X = <<20+12+X=51>>51 kuanzia Jumatatu hadi Jumatano.
Hivyo X = 51 - (20 + 12) = <<51-(20+12)=19>>19 kurasa.