## Math Problem Statement

Zizi had some cards. She could place them into sets of 4 cards or sets of 6 cards without leaving any remainder. When she placed them into sets of 7 cards instead, she needed one more card to make the last set of 7. What was the smallest possible number of cards she had?

## Solution

## Math Problem Analysis

### Mathematical Concepts

Number Theory

Modular Arithmetic

### Formulas

Least Common Multiple (LCM)

Modular Congruences

### Theorems

Chinese Remainder Theorem

Multiplicative Inverse Modulo

### Suitable Grade Level

Grades 9-12