Mensuration Ques 34
Question
The sum of the radius and height of a right circular cylinder (A) is 31 metre. The total surface area of the cylinder is $1364 m^{2}$. If the radius of another right circular cylinder (B) is 3.5 metre more than the radius of cylinder (A), what is the circumference of base of cylinder (B) ? (in metre)
(1) 64
(2) 66
(3) 80
(4) 88
(5) 44
(IBPS RRBs Officers CWE (Prelim Exam) 10.09.2017)
Show Answer
Correct Answer: (2)
Solution: (2)
For cylinder A,
$r+h=31$ metre
$\because$ Total surface area $=1364$ sq. metre
$\Rightarrow 2 \pi r(h+r)=1364$
$\Rightarrow 2 \times \frac{22}{7} \times r \times 31=1364$
$\Rightarrow r=\frac{1364 \times 7}{2 \times 22 \times 31}=7$ metre
$\therefore$ Radius of the base of cylinder B $=(7+3.5)$ metre $=10.5$ metre
$\therefore$ Circumference of base $=\left(2 \times \frac{22}{7} \times 10.5\right)$ metre $=66$ metre
BETA
