Important question on Set for JEE main+advanced| By Er. Deepak pandey Sir

Suppose A 1​ ​,A 2​ ​,.....,A 30​ ​are thirty sets each with five elements and B 1​ ​,B 2​ ​,.....,B n​ ​are n sets each with three elements such that ⋃ i=130​ ​A i​ ​=⋃ j=1n​ ​B j​ ​=S and each element of S belongs to exactly 10 of the A i​ ​'s and exactly 9 of the B j​ . then what is n?