Question

First car-park has 7 times less sport cars than the second car-park. After 36 sport cars were moved from the second car-park to the first one, the number of sport cars in both car-parks became the same. How many sport cars did second car-park have originally?

Answer 1

Sport cars in second car-park originally are = 84

Explanation:

Let,

The number of sports cars in first parking be =x

Number of sports care in second parking be =y

First parking has 7 times less sports cars than second,so x = y/7

After 36 sport cars were moved from the second car-park to the first one, our equation becomes:

x + 36 = y- 36

solving the above both equations

x=y/7

y = 7x ------- (1)

and

x + 36 = y- 36

y = x +72 -------(2)

Substituting eq 1 into eq 2 we get,

7x = x + 72

6x = 72

now, we get x = 12 ( sports cars in 1st parking)

putting value of x in eq (1)

y = 7x

y = 7*12

y= 84 ( sports cars in 2nd parking)

Answer 2

Originally the first car park had 12 sport cars and the second car park had 84 sport cars.

Explanation:

Let the no. of sport cars in first and second car park be x and y respectively.

x = y/7

x + 36 = y- 36

Solving the system of equations,

y = 7x

y = x +72

Substituting y = 7x in the above equation,

7x = x + 72

6x = 72

x = 12

y = 7x = 7*12 = 84

y = 84

∴ Originally the first car park had 12 sport cars and the second car park had 84 sport cars.