Let Ramesh's marks = x.

Bishnu scored 52%, and his marks are 23 less than Ramesh:

52% of total = x − 23

Asha scored 64%, and her marks are 34 more than Ramesh:

64% of total = x + 34

Subtract:

64% − 52% = 34 + 23 = 57

So, 12% = 57

Therefore, 1% = 4.75

Geeta scored 84%:

84 × 4.75 = 399

let total marks of the exam =100x bishnu=52% ie ;52x asha=64x ramesh=52x+23 also ramesh =64x-34 equating both 52x+23=64-34 12x=57 x=4.75 therefore total marks is 100x =100*4.75=475 total marks of the exam is 475 now geeta score is 84% 84/100 *475=21*19=399 hope it helps