Simplify the following text for a Grade 11 native English-speaking person.
Original: In nearly two-thirds of American mosques , women pray behind partitions or in separate areas , not in the main prayer hall ; some mosques do not admit women at all due to the lack of space and the fact that some prayers , such as the Friday Jummah , are mandatory for men but optional for women .
Simplified: In nearly two-thirds of American mosques , women pray behind partitions or in separate areas , not in the main prayer hall ; some mosques do not admit women at all .