When did the Indian Constitution come into

What will come in the place of question mark (?) in the given expression?

? = 12.5% of 25% of 20% of 1280 + 1248

26 ² – 13% of 400 + (529 ÷ 23 ² ) = ? ² 

(60 × 8 ÷ 10) × 5 = ?

1200% of 18 + √1600 + 6² = ?² + (90 of 0.4)

116*2/3% of 18600 + 666*2/3% of 1290 = 457*1/7% of 1750 + 555*5/9% of 3150 + ?

(22.5 × 24) ÷ 40 + 51.50 = ? ÷ 5.25

What will come in place of (?) in the given expression.

(3/4 of 64) + (1/2 of 48) = ?

15 * 12 + 35% of 80 + 70% of 130 = ?

45% of 360 - 160 + ? = √324

6 0 - 20 [8 + 12 {8-8 (20-12)+20}-40] ÷ 16 =?