In a series of races, 10 toy cars are raced, 2 cars at a time. If each

Question

In a series of races, 10 toy cars are raced, 2 cars at a time. If each car must race each of the other cars exactly twice, how many races must be held?

A. 45
B. 90
C. 180
D. 200
E. 220

Archit3110 · Answer

total cars = 10 
10c2*2 = 90
IMO B

snehaluk · Answer

Total pool of car = 10 cars
2 cars compete each other hence group of 2 cars ..group=combination problem it is.

hence 10C2=45

now this will happen twice(i.e. each car must compete with other car twice) , multiply 45 by 2 =90

Therefore option 'B' is correct.

ScottTargetTestPrep · Answer

Solution:

If each car only races one another exactly once, then there are 10C2 = (10 x 9)/2 = 45 races. However, since each car races each of the other cars exactly twice, there are a total of 45 x 2 = 90 races.

Answer: B

bumpbot · Answer

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In a series of races, 10 toy cars are raced, 2 cars at a time. If each

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In a series of races, 10 toy cars are raced, 2 cars at a time. If each

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