Official solution
Given,
Number of Indians = 6
Number of foreigners = 8
Committee of at least 2 Indians and double number of foreigners is to be formed. Hence, the required cases are
(2I, 4F) + (3I, 6F) + (4I, 8F)
= \[{}^6{C_2} \times {}^8{C_4} + {}^6{C_3} \times {}^8{C_6} + {}^6{C_4} \times {}^8{C_8}\]
= (15 \[\times\] 70) + (20 \[\times\] 28) + (15 \[\times\] 1)
= 1050 + 560 + 15 = 1625