Question 634233
At 11 o'clock this morning, mel's parking lot was full.
 Mel noticed that the ratio of cars to trucks was 5:2.
 By 1 o'clock in the afternoon, 10 trucks had left the lot and 10 more cars
 had parked in the lot.
 The ratio of cars to trucks was then 6:1.
 How many vehicles are Parked in mel's parking lot when the lot is full?
:
Let x = the multiplier
then when the parking lot was full:
5x = no. of cars
2x = no. of trucks
:
" By 1 o'clock in the afternoon, 10 trucks had left the lot and 10 more cars
 had parked in the lot. The ratio of cars to trucks was then 6:1. "
{{{(5x+10)/(2x-10)}}} = {{{6/1}}}
Cross multiply to find x
5x + 10 = 6(2x-10)
5x + 10 = 12x - 60
10 + 60 = 12x - 5x
70 = 7x
x = 10
therefore originally there were:
5(10) = 50 cars
2(10) = 20 trucks
(when the parking lot was full)