Number of large buildings = 22
Number of small buildings = 15
Number of floors in 1 large building = 10
Number of apartments on 1 floor = 2
∴ Total apartments in 1 large building = 10 × 2 = 20
Similarly,
Total apartments in 1 small building = 12 × 3 = 36
∴ Total apartments in the entire housing complex = (22 × 20) + (15 × 36)
= 440 + 540
= 980