From 1962 to 2011, how many coaches received both NBA and ABA awards?
from 1962 to 2011 refers to year between 1960 and 2011; received both NBA and ABA award refers to coachID where award LIKE 'NBA%' and 'ABA%'
SELECT COUNT(DISTINCT coachID) FROM awards_coaches WHERE year BETWEEN 1962 AND 2011 AND award = 'ABA Coach of the Year' AND coachID IN ( SELECT coachID FROM awards_coaches WHERE year BETWEEN 1962 AND 2011 AND award = 'NBA Coach of the Year' )