Correct Answer  Option 3 : Three
Given: Seven persons, A, B, C, D, E, F and G go on a vacation on different days of week, Monday, Tuesday, Wednesday, Thursday, Friday, Saturday and Sunday but necessarily in the same order.
1) G goes on Friday.
2) One person goes between G and C.
Days

Case 1

Case 2

Monday



Tuesday



Wednesday

C


Thursday



Friday

G

G

Saturday



Sunday


C

3) D goes on the second day of the week.
4) Three persons go between D and F.
Days

Case 1

Case 2

Monday



Tuesday

D

D

Wednesday

C


Thursday



Friday

G

G

Saturday

F

F

Sunday


C

5) The number of persons goes after C is equal to the number of persons go before G.
Here, case 2 will be cancelled.
6) A goes on one of the days before C.
7) B does not go on Monday or Thursday.
Days

Person

Monday

A

Tuesday

D

Wednesday

C

Thursday

E

Friday

G

Saturday

F

Sunday

B

So, the above shown arrangement is the final order of them going to the vacation.
Days

Person

Alphabetical Order

Monday

A

A

Tuesday

D

B

Wednesday

C

C

Thursday

E

D

Friday

G

E

Saturday

F

F

Sunday

B

G

Hence, if all the persons go to vacation in alphabetical order starting from Monday, the position of 3 persons would not change.