Circumference: 2× 3. 14× 5 = 3 1.4 (cm)
Area: 3. 14× 5× 5 = 78.5 cm2.
Question 2: The area of a circle is the largest.
Radius = 62.8 ÷ 3.14 ÷ 2 =10m.
Area =10×10× 3.14 = 314 square meter.
Question 3: The price of bicycle before discount is X yuan.
X 85%=357
X = 420
That is, the price of this bicycle before discount is 420 yuan.
Question 4: Set the full text to ***X words.
X 40%= 1600
X=4000
Namely: the full text ***4000 words.
Also: 4000- 1600=2400 (pieces) not hit.