Jin is 3 floors above ground level in a hotel. Leila is on a parking level of the hotel that is 4 floors below ground level. How many floors are they apart are they? Draw a number line to show 3 - (-4).

Step-by-step explanation:

Consider the ground level as 0 (zero)

Jin is 3 floors above ground level in a hotel.

Hence Jin is in third floor from the ground level (0,1,2 and 3rd floor)

Leila is on a parking level of the hotel that is 4 floors below ground level.

Since the parking is below, it is named as -4 th floor (0, -1, -2, -3 and -4th floor)

They are part by 7 floors, 3 - (-4) = 7

Refer the attachment for number line diagram

linearly: 8560 bacteria

exponentially: approximately 75233 bacteria

step-by-step explanation:

assuming it is not exponential (we would have some really complicated logarithms), let's say it is linear. then, after 5 hours, it increased by 1200 bacteria, so every hour it increases by 240 bacteria. this means that after 19 hours, we get 19 * 240 + 4000 bacteria or 3800 + 760 + 4000 = 7800 + 760 = 8560 bacteria.

because it says round your answer, i will do this exponentially (with a calculator, of course). first, we need to find how much it multiplies by every hour, by taking the 5th root of 52/40 or 13/10. this is approximately 0.167. we still need to add 1 to this, because we are multiplying by that number, not adding that amount of the number. now, we just calculate 4000 * (1.167)^19. use a calculator to get approximately 75232.6, or 75233.

step-by-step explanation:

1. practice, practice & more practice

2. review errors

3. master the key concepts

do not try to memorise the processes.

4. understand your doubts.

5. create a distraction free study environment

6. create a mathematical dictionary

7. apply maths to real world problems.