Question

If the radii of the ends of a bucket 45 cm high are 28 cm and 7 cm respectively. The total surface area of the bucket is:

• A. 6074 $c{m}^2$
• B. 7074 $c{m}^2$
• C. 8074 $c{m}^2$
• D. 8274 $c{m}^2$

Answer 1

The correct option is C

8074 $c{m}^2$

Total surface area of the bucket

= TSA = $\pi \times l\times (r_1+r_2)+\pi \times ({r_1}^2+{r_2}^2)$ ;

Where $\pi =\frac{22}{7}$ ,

l = Slant height of the bucket = $\sqrt{(45{)}^2+(21{)}^2}$ cm = 49.6 cm ,

$r_1=28cm$ and $r_2$ = 7cm

Therefore,

TSA = $[\frac{22}{7}\times 49.6\times (28+7)+\frac{22}{7}\times ({28}^2+7^2\left)\right]c{m}^2=8074c{m}^2$ .