Question

There are 2 red cars and 3 blue cars. The 5 cars contain a total of 12 people. No car has more than 4 people. Every car has at least 1 person. The only cars with the same number of people are the red cars. How many people are in 1 red car?

Answer 1

2 people are in one red car

1 red car = 2
2 red cars = 4
1st blue car = 1
2nd blue car = 3
3rd blue car = 4

So 2+2+1+3+4 = 12

:)

Answer 2

Number of people in each of the red cars --- x , x ≤ 4
leaves 12-2x for all other people in blue cars.

if x = 1, blue cars contain 10 people
sums with a total of 10 with different numbers, none > 4 , none the same : ----- can't find any

if x = 2, blue cars contain 8 people
sums with a total of 8 with different numbers, none > 4 , none the same : ----- 1,3,4 ------ (1+3+4=8)
This is K's solution

if x = 3, blue cars contain 6 people
sums with a total of 6 with different numbers, none > 4 , none the same : ----- 1,2,3 ------ (1+2+3 = 6)
But that would mean a blue car AND a red car have 3, which is not possible

if x = 4, blue cars contain 4 people
sums with a total of 4 with different numbers, none > 4 , none the same : ----- can't find any

Only possible answer: Each of the red cars holds 2 people

R R B B B
2 2 1 3 4

Answer 3

Thank you guys so much