Islam in Mongolia is practiced by approximately 3 to 5% of the population.[1][2] It is practised by the ethnic Kazakhs of Bayan-Ölgii Province (88.7% of total aimag population) and Khovd Province (11.5% of total aimag population, living primarily in the Khovd city, Khovd sum and Buyant sum) aimag in western Mongolia. In addition, a number of small Kazakh communities can be found in various cities and towns spread throughout the country.
https://en.wikipedia.org/wiki/Islam_in_Mongolia
Mongols can't read books))