Answer:
4
Step-by-step explanation:
1. if the mass of coffee worth $10 is 'x', then its worth is 10x, and the worth of the mixture is 5(x+20);
2. using the previous item it is possible to write the next equation:
5(x+20)=4*20+10*x; ⇒ x=4.
3. the required mass is 4 pounds.
Its 37 and yea its an easy question lol
Answer:

Step-by-step explanation:
Given that , the sum of the first nine terms of an arithmetic series is 162 and the sum of the first 12 terms is 288.

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<u>Related</u><u> </u><u>Infor</u><u>mation</u><u> </u><u>:</u><u>-</u><u> </u></h3>
• The sum of n terms of an AP is
• nth term of an AP is given by ,

It can help because 9×4 =36, and 9×8=72. if you divide 72 by 2 you get 36 which is the answer to 9 ×4. basically because nine is the same in both problems you are multiplying by 4 (and you know 4 is half of 8) you can assume that multiplying the sum of 4 and 9 that you will get the sum of 8 and 9.
The perimeter will be the perimeter of the real thing divided by 1.2 .
The area will be the area of the real thing divided by (1.2)² .