Question

In a car park the ratio of white cars to black cars is 2:7. The ratio of white cars to red cars is 3:11. Altogether there are 343 white, black and red cars.
How many black cars are in the car park?

Answer 1

$\texttt{white:black}$

$\texttt{2:7}$

7:2 black:white

$\texttt{white:red}$

$\texttt{3:11}$

7:2

3:11

21:6:22

(21/(21+6+22))×343 black cars

Answer 2

Concept Introduction: Ratio is the basic concept of Mathematics.

Given:

We have been Given: The ratio of white cars to black cars is

$2 : 7$

and ratio of white cars to red cars is

$3: 11$

total number of cars,

$343$

To Find:

We have to Find: How many black cars are in the car park?

Solution:

According to the Problem, Let the number of cars be

$x$

therefore,

$2x + 7x + 3x + 11x = 343 \\ 23x = 343 \\ x = \frac{343}{23} \\ x = 15$

the number of black cars are

$7x = 7 \times 15 = 105$

Final Answer: The number of black cars is

$105$

#SPJ2