In the mall's parking lot, there are three times as many cars as trucks. The number of motorcycles is twice the number of bikes and there are four times as many trucks as bikes. If the total number of vehicles is 285, how many cars are there?

1 Answer
Feb 19, 2018

"Hence, the number of cars is x_1=180"

Explanation:

"Let "x_1 "denote the number of cars"
"Let " x_2 "denote the number of trucks"
"Let "x_3 "denote the number of motorcycles"
"Let "x_4 "denote the number of bikes"
"Given:"
3x_1=x_2
2x_4=x_3
x_2=4x_4
x_1+x_2+x_3+x_4=285
x_1=?

3x_1=x_2implies
x_2=1/3x_1

x_2=4x_4impliesx_4=1/4x_2=1/4xx1/3x_1

x_4=1/12x_1

2x_4=x_3implies x_3=2x_4=2xx1/12x_1
x_3=1/6x_1

The sum of cars is 285

x_1+x_2+x_3+x_4=285

x_1+1/3x_1+1/6x_1+1/12x_1=285

(1+1/3+1/6+1/12)x_1=285

(12/12+4/12+2/12+1/12)x_1=285

(12+4+2+1)/12x_1=285

19/12x_1=285

x_1=285/19xx12

x_1=15xx12

x_1=180

x+2=1/3x_1=1/3xx180=60

x_2=60

x_3=1/6x_1=1/6xx180=30

x_3=30

x_4=1/12x_1=1/12xx180=15

x_4=15

x_1+x_2+x_3+x_4=180+60+30+15

x_1+x_2+x_3+x_4=285

Verified

"Hence, the number of cars is x_1=180"