What is the total number of girls who visited Delhi, Mumbai and Varanasi together?
484
From the given information we can get
Number of boys =1200×45100 = 540
Number of girls =1200−540=660
Number of girls visiting Mumbai =660×30100 =198
Number of girls visiting Delhi =660×25=264
Number of girls visiting Jodhpur =2642=132
Number of girls visiting Kolkata =23×(660−198−264−132)=23×66=44
Number of girls visiting Varanasi =660−198−264−132−44=22
Number of boys visiting Mumbai = Total number of students who visited Mumbai - number of girls visiting Mumbai =300−198=102
Number of boys visiting Delhi =540×20100=108
Number of boys visiting Jodhpur =540×40100=216
Number of boys visiting Kolkata =12×(540−102−108−216)=12×114=57
Number of boys visiting Varanasi =540−102−108−216−57=57
The total number of girls who visited Delhi, Mumbai and Varanasi together =264+198+22=484