What will come in place of "?" in the following questions. `5/11` of `297xx 39-:13+?=299-:23+453`

What will come in place of question mark(?) in the following questions? 8305(1/7xx1/5xx?)=199320

What will come in place of question mark (?) in the following questions ? 12.4 xx 13.2 xx 13.3 = ?

What will come in place of question mark (?) in the following questions ? 13.6 xx 13.6 + 3.5 xx 0.5 = ? + 11.42 xx 3.2

What will come in place of question mark (?) in the following questions ? 11.42 xx 18.6 - 52.68 = ?

What will come in place of question mark(?) in the following questions? (45xx 4.5 xx 3.2) + 343 =?

What will come in place of question mark (?) in the following equation? (15/11) xx 143 + 30 = ?^2

What will come in place of question mark (?) in the following questions ? 13.31 + 33.321 - 241.11 = ?

What will come in place of question mark (?) in the following questions ? (2)/(5) of (13)/(4) of (5)/(26) of ? = 32.5

What will come in the place of question mark (?) in following questions? 7777-11 xx 7= ? +2323