Question

There are 7 different books in a library.
A girl can borrow book B if only book A is borrowed.
In how many ways can she borrow 3 books ?

Answer 1

\(\large \color{black}{\begin{align}
& \normalsize \text{There are 7 different books in a library. }\hspace{.33em}\\~\\
& \normalsize \text{A girl can borrow book B if only book A is borrowed.} \hspace{.33em}\\~\\
& \normalsize \text{In how many ways can she borrow 3 books ?} \hspace{.33em}\\~\\
& a.)\ 15 \hspace{.33em}\\~\\
& b.)\ 20 \hspace{.33em}\\~\\
& c.)\ 25 \hspace{.33em}\\~\\
& d.)\ 30 \hspace{.33em}\\~\\
\end{align}}\)

Answer 2

is there any specific arrange for A and B ?

Answer 3

```
A girl can borrow book B if only book A is borrowed
```
Must book A be borrowed by the girl or by someone else?

Answer 4

25

Answer 5

book B can be borrowed only if book A is borrowed

Answer 6

yes 25 is answer given , how u got it

Answer 7

I am confused by the question. But phi is not :)

Answer 8

"A girl can borrow book B if only book A is borrowed"

i think "Must book A be borrowed by the girl "

Answer 9

lol m also confused by thhe question

Answer 10

"A girl can borrow book B if only she also borrows book A"
is the intended wording if 25 is the final answer.

Answer 11

First, order does not matter.

I broke the problem into two parts.
say one of the 3 books we choose is A. then we have a choice of 6C2 for the other two. that is 15 combinations

say we did not choose A. then that means we can not choose B either.
that leaves 5 books from which to choose 3
5C3= 10 more combinations

15+10= 25

Answer 12

"A girl can borrow book B if only she also borrows book A"
is the intended wording if 25 is the final answer.

yea i think so ,

Answer 13

thnx