When Ramon looked out at the school parking lot, he noticed that for every 3 minivans, there were 7 other types of vehicles. If there are a total of 150 vehicles in the parking lot, how many of them are minivans?

Step-by-step explanation:

If there were 3 vans for every 7 cars, then there were 3 vans for every 10 of the total in the lot. Use a proportion to solve this:

and cross multiply to get

10x = 450

so x = 45

There are 45 vans in the lot.

step-by-step explanation:

the original amount doesn't ''re just looking for the time it takes for 1/2 of the substance to we have

(1/2) =)     take the ln   of both sides

ln (1/2)   = )   and we can write

ln(1/2) = ) lne     and lne   = 1     so we have

ln(1/2) = -.1092t     divide both sides by -.1092

t = ln(1/2)/-.1092 = about 6.347 days = about 6.3 days (rounded)

the answer would be 150 books

step-by-step explanation:

if you divide 300 by 2 you will get 150