What is the full form of 'CHA'?

Simplify the following expression:

    (400 +175) ² - (400 – 175) ² / (400 × 175)

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

?% of (112 X 3 + 164) + 75 = 2 X 140 + 35

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

(√? - 17) X 40 + 145 = 1000 - 15 

[(11)² - (12)² + (5)³]² = ?

? = 6.25% of 240 + 25 ² + 17 ² – 16 × 17

(22.5 × 24) ÷ 40 + 51.50 = ? ÷ 5.25

(6² - 5² ) % of 800 = 22 X √?

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

18 × 16 – 11 × 4 = 15² + ?

Find the simplified value of the given expression.

(1/4) of {6⁴ - 28 x 15 + 13 x 16 - 12.5 of 12²}