Question

Irina rakes leaves for $9.75 per hour. She works 10 times per month, and each job lasts 2.25 hours. Which equation would provide the best estimate of how many dollars Irina earns each month? 9 × 10 × 2 = 180 9 × 10 × 3 = 270 10 × 10 × 2 = 200 10 × 10 × 3 = 300

Answer 1

The answer is 10x10x2=200

Explanation:

Firstly, we need to define some variables:

P=Irina's earns=9.75 $/hours

M=Irina's worked days=10 days

H=Irina's worked hours=2.25 hours/days

We can approximate "H" from 2.25 to 2.00 and "P" from 9.75 to 10.00.

So, Irina earns each month:

`P*H*M\\10*10*2\\200`

When you approximate a number, the idea is to simplify the number to a whole number. This number is the nearest to the previous o next whole number.

Finally, the answer is 10x10x2=200

Answer 2

For this case the real step will be given by:
(9.75) * (2.25) * (10) = $ 219,375
Therefore, the best approximation is given by:
(10) * (2) * (10) = $ 200
The difference is:
219,375 - 200 = $ 19,375
Answer:
the best estimate of how many dollars Irina earns each month is:
10 × 10 × 2 = 200