Question

Nadia has 20 more postcards then Pete. After Nadia gives Pete some cards Pete has 2 more postcards than Nadia. How many postcards does Nadia give to Pete?

Answer 1

Answer:

11 postcards.

Step-by-step explanation:  

Let x be the number of postcards that Pete have. Let y be number of postcards that Nadia gave to Pete.

We are told that Nadia has 20 more postcards then Pete. So Nadia will have x+20 postcards.        

We are also told that after Nadia gives Pete some cards Pete has 2 more postcards than Nadia. We can represent this information as:

$x+y=(x+20-y)+2$  

Let us solve for x.

$x+y=x+20-y+2$  

Add y to both sides of equation.

$x+y+y=x+20-y+2+y$  

$x+2y=x+22$  

Subtract x from both sides of equation.

$x+2y-x=x+22-x$  

$2y=22$  

$y=\frac{22}{2}$  

$y=11$  

Therefore, Nadia gave 11 postcards to Pete.