Which letter-cluster will replace the question mark (?) to complete the given series?

HSDA, IZQT, ?, KNQF, LUDY

In a certain code language, 'DANCE' is written as 'ADNEC' and ‘DISCO’ is written as ‘IDSOC’. How will 'DREAM' be written in that language?

If I denotes ‘÷’, J denotes ‘×’, K denotes ‘−’ and L denotes ‘+’, then what will come in place of ‘?’ in the following equation?
 37 L 25 K (14 J 2) L (2 J 13) K (62 I 31) = ?

Question figure.

Which letter-cluster will replace the question mark (?) to complete the given series?
 XAPE, BIBU, ?, JYZA, NGLQ

09 April 2023 is Friday. What will be 30 April 2023?

Study the given pattern carefully and select the number that can replace the question mark (?) in it.
 First row – 13, 50, 104
 Second row – 11, 42, ?
 Third row – 18, 70, 144
 (NOTE: Operations should be performed on the whole numbers, without breaking down the numbers into its constituent digits. E.g. 13 – Operations on 13 such as adding /deleting /multiplying etc. to 13 can be performed. Breaking down 13 into 1 and 3 and then performing mathematical operations on 1 and 3 is NOT allowed)

select the correct mirror image of the given combination when the mirror is placed at MN as shown.