In many Jewish synagogues a minyan is required for public prayer times. A minyan is a group of at least 10 Jewish men over the age of 13 years old. A minyan is not required, of course, for personal prayer times a person might have.
Even though the number 10 is a very significant number, there is no biblical support for the requirement of a minyan in order to have public prayer. The scriptures do encourage coming together for worship services. Worshipping together, praying together and fellowshipping together are all important aspects in our walk with GOD.
Picture originally found here