The ratio of the number of English books to Hindi books

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

18 × 16 – 11 × 4 = 15² + ?

If a nine-digit number 389x6378y is divisible by 72, then the value of √(6x + 7y) will be∶

(22.5 × 24) ÷ 40 + 51.50 = ? ÷ 5.25

(115 × 17 × 3)/(23 × 51) + ?³ = √169

180 ÷ 3 of  2 = 102 – ?

6612 ÷ 19 - ?% of 240 = -2196

54% of 250 = 6 × 21 + √?

What value should come in place of the question mark (?) in the following question?

45 × 2 + 180 ÷ 6 − 12 = ?  

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

59.92 × 15.11 + √4224 = ? + 144.9 

Evaluate: {2 x (0.718 + 0.982) + 0.008 of 5000}