Correcting links and tuple indexing

src/1.md

@@ -89,7 +89,7 @@ We'll talk about type annotations and inference later.
 
 ## Types
 
-### Basic Types ([3.2](https://doc.rust-lang.org/book/ch03-05-control-flow.html))
+### Basic Types ([3.2](https://doc.rust-lang.org/book/ch03-02-data-types.html))
 
 Rust has the following numeric types:
 
@@ -118,7 +118,7 @@ let heart_eyed_cat = '😻';
 
 `char`s in Rust are four bytes in size, as a char is meant to represent a single Unicode scalar value, meaning it can do much more than just ASCII.
 
-### Primitive Compound Types ([3.2](https://doc.rust-lang.org/book/ch03-05-control-flow.html))
+### Primitive Compound Types ([3.2](https://doc.rust-lang.org/book/ch03-02-data-types.html))
 
 Rust has tuples, which are used extensively. Tuples can be non-homogenous and of any length.
 
@@ -132,8 +132,7 @@ Tuples are accessed using dot syntax, or destructured by pattern matching (more
 ```rust
 # let tup = (1, 2);
 # let trip: (char, i32, f64) = ('A', -2, 100.01);
-let one = tup.0;
-let minus_two = trip.2;
+let one = tup.0 + tup.1 + trip.1;
 let (x, y) = tup;
 let (c, i, _) = trip;
 ```
@@ -341,7 +340,7 @@ fn zip(fst: i32, snd: i32) -> (i32, i32) {
 
 Note how in the last examples the `return` keyword was not used and there is no semicolon. This is because in Rust, (almost) everything is an expression that returns a value, even blocks. The value of the last expression in a block is the return value of the block. Ending an expression with a semicolon discards the return value. This can be a tricky concept to grasp, see [Rust by Example](https://doc.rust-lang.org/rust-by-example/expression.html) for more detail.
 
-## Control Flow ([5.5](https://doc.rust-lang.org/book/ch03-05-control-flow.html))
+## Control Flow ([3.5](https://doc.rust-lang.org/book/ch03-05-control-flow.html))
 
 ### `if` Expressions
 
@@ -553,4 +552,4 @@ fn main() {
         number = maybe_collatz(number);
     }
 }
-```
+```