A cylindrical pillar has a radius of 7 cm, and its curved surface area is 1,320 cm². What is its volume? Take $\pi = \frac{22}{7}$ .

1,320 cm³Correct answerYour answer2,310 cm³Correct answerYour answer4,620 cm³Correct answerYour answer9,240 cm³Correct answerYour answer

Show the answer and explanation

CorrectNot quiteAnswer C

Correct answer: C

Curved surface: $2 \times \frac{22}{7} \times 7 \times h = 44h = 1320$ , so $h = 30$ cm.
Volume = $\frac{22}{7} \times 7 \times 7 \times 30 = 4620$ cm³.

Worth noting

9,240 cm³ comes from using $\pi rh = 1{,}320$ (dropping the 2), which doubles the height to 60 cm.

Ten questions from Mensuration: Areas and Volumes, at your own pace.

Ten questions from Mensuration: Areas and Volumes, at your own pace.

A cylindrical pillar has a radius of 7 cm, and its curved surface area is 1,320 cm². What is its volume? Take π=227\pi = \frac{22}{7}π=722​.