Answer: The number of different combinations of 2 vegetables are possible = 15 .
Step-by-step explanation:
In Mathematics , the number of combinations of selecting r values out of n values = 
Given : Number of available vegetables = 6
Then, the number of different combinations of 2 vegetables are possible will be :

Hence , the number of different combinations of 2 vegetables are possible = 15 .
We have to calculate speed for 1 lap for all of 'em.
Cutwright - 84/35 = 2.4 mins for 1 lap
Evans- 96.6/42 = 2.3 mins for 1 lap
Liza- 102.6/38 = 2.7 mins for 1 lap
So, EVANS drove fastest among them as he took less time...
The answer is 20 days.
After 60 people have joined there will be 460 people in the camp.
The number of days which the provisions will last will be proportional less after the 60 people have joined and will be:-
(400/460) * 23
= (20 / 23) * 23
= 20