Answer: She bought 8 pairs of shoe laces.
Explanation:
Hi, to answer this question we have to analyze the information given: 
- Total cost: $9.60 
- Cost of each pair of shoe laces: $1.20 
So, to calculate the number of pairs of shoe laces we have to divide the total amount spend ($9.60) by the cost of each pair of shoe laces ($1.20) 
Mathematically speaking: 
9.60 / 1.20 = 8 pairs of shoe laces.