Let x be the score Amaya gets on the final test. She wants her average of all 3 tests to be between 80 and 89:
<span>80 ≤ (78 + 91 + x) / 3 ≤ 89 </span>
<span>Multiply everything by 3: </span>
<span>240 ≤ 78 + 91 + x ≤ 267 </span>
<span>240 ≤ 169 + x ≤ 267 </span>
<span>Subtract 169 from everything: </span>
<span>240 - 169 ≤ x ≤ 267 - 169 </span>
<span>71 ≤ x ≤ 98 </span>
<span>Answer: </span>
<span>She needs to score between 71 and 98 to get a B for the course.</span>
Answer:
the surface area is 3140 square feet
Step-by-step explanation:
The computation of the surface area is given below:
Given that
Diameter = 20 feet
radius = 20 ÷ 2 = 10 feet
Surface area =
= 2 × 3.14 × (10)^2 + 2 × 3.14 × 10 × 40
= 6.28 × 100 + 6.28 × 400
= 628 + 25.12 × 100
= 628+ 2512
= 3140 square feet
hence, the surface area is 3140 square feet
Answer: 1.5s+20
Step-by-step explanation: