how many slices of mangos are needed for 10 cups of yogurt

It would depend on the size of the mango slices and how much mango you would like in each cup of yogurt.

As a general estimate, if each cup of yogurt requires about 1/4 cup of mango slices, you would need approximately 40 slices of mango for 10 cups of yogurt.

However, you may want to adjust the amount of mango slices based on your personal preference and the size of the slices.