Food allergies happen when the body’s ______ system

15% of 695 – 12.5% of 250 =? – 1200

7/11 × 1034 + 1(4/7) × 2401 = 1230 +?

33 × ?² – 6 × 5 = 3270

648 ÷ 36 × 49 – 1012 + 847 = ?

20% of 10% of 900 + 84/12 = ?²

√64 of √225 = √(25 + ?) X 12

Find the simplified value of the given expression: 18 × 3 ÷ 6 + 24 ÷ 4 of 2 − 60 ÷ 2 of 3 + 18 × 5 ÷ 9. 

2(1/3) + 2(5/6) – 1(1/2) = ? – 6(1/6)

Find the simplified value of the given expression:

{16 of 13 - 7² + √441 - (3/4) X 64} ÷ (102 ÷ 17)

(180 ÷ 2² ) ÷ (60% of 30) = (? ÷ 2)