Answer:
10 times 15.2 is 152, 1/10 of 15.2 is 1.52
Step-by-step explanation:
The wall can be built in 22 days by 6 workers in first 6 days and 9 workers in the rest of time.
<h3>How to use inverse proportionality to determine building time of a wall</h3>
In this question we must use the definition of <em>inverse</em> proportionality, in which the number of workers (
), no unit, is inversely proportional to the <em>building</em> time (
), in days.
According to the statement, 6 workers spent 6 days building a wall and there are 24 days left for completion, but 3 more workers entered to reduce building time, which can be represented by the following expression:


In this scenario, the wall can be built in 22 days. 
To learn more on inverse proportionality, we kindly invite to check this verified question: brainly.com/question/4838941
The first one is 4•7 I believe
Let's find the area of the outer circle and the inside circle
the inside's circle area
A= π x 6²=36<span>π
the outer's
A' = </span>π x 4x²= 4<span>πx²
A'-A=4</span>πx²- 36π=160πcm² equivalent to x²- 9=40, so x²=49 implies x =sqrt(49)=7, x=7<span>
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