Answer:
<em>19800 seconds, or 330 minutes, or 5 hours + 30 minutes</em>
Step-by-step explanation:
<u>Number Permutations</u>
We know the phone number has 7 digits, 4 of which are known by Mark. This leaves him 3 digits to guess with. We also know the last one is not zero. The number can be represented as
XXY
Where X can be any digit from 0 to 9 and Y can be any digit from 1 to 9. The first two can be combined in 10x10 ways, and the last one can be of 9 ways, this gives us 10x10x9 = 900 possible permutations.
If each possible number takes him 22 seconds, every possibility will need
22x900=19800 seconds, or 330 minutes, or 5 hours + 30 minutes
This is not my work but i hope this can help you with your problem
https://answers.yahoo.com/question/index?qid=20120518194118AAhi738
Answer:
10x^2 - 4x
Step-by-step explanation:
5x - 2 times 2x will equal the area of 'Potatoes.'
5x times 2x is 10x^2.
2 times 2x is 4x.
I cannot provide an exact value because x hasn't been identified.
I hope this helps.