A room with poor air quality has a particle concentration of 80 units. A fan removes 50% of the remaining particles each hour. What is the particle concentration, in these same units, in the room after 2 hours?

20 units

Step-by-step explanation:

Initial particle concentration = 80 units

Particles removed each hour = 50% of the remaining particles

To find:

Particle concentration after 2 hours = ?

Solution:

Particles removed in 1 hour = 50% of remaining particles

i.e. Particles removed in 1 hour = 50% of initial concentration

Particles removed in 1 hour = 50% of 80 = 40

Particles removed in next 1 hour = 50% of remaining particles

i.e. Particles removed in next 1 hour = 50% of concentration after 1 hour

Particles removed in next 1 hour = 50% of 40 = 20

Total particles concentration removed in 2 hours = 40 + 20 = 60 units

Therefore, particle concentration after 2 hours = Initial concentration - Total particle concentration removed in 2 hours

= 80 - 60 = 20 units

answer: you need the equation in the question so i can answer it

step-by-step explanation:

the final amount you will pay is $68.04.

the tip is determined by the pre-tax amount, so we calculate the tip based on the original bill, not after we've added sales tax.

to find the tip:

we can divide 54.00 by 100 to get 1% of 54. then we multiply that by 18.

54 / 100 = .54

.54 x 18 = 9.72

tip = 9.72$

to find the tax:

we can divide 54.00 by 100 to get 1% of 54. then we can multiply that by 8 to get 8%.

54 / 100 = .54

.54 x 8 = 4.32

tax= 4.32

now we can add the tip and tax to the bill to get our total.

54 + 9.72 + 4.32 = 68.04

total: $68.04

step-by-step explanation: