Question

the volume of open cylindrical can is 6358 cm3 and its height is 28 cm. find its radius and curved surface area

Answer 1

Volume of cylinder = 22/7 * r * r * h
h = 28
22/7 * r *r * 28 = 6358
88*r*r = 6358
r*r = 6358/88
r*r = 72.25
r = square root of 72.25
r = 8.5
Ans: 8.5 cm
and curved surface area= 2πrh
=2×π×8.5×28
=1495.39 cm^2

Answer 2

given,
volume of cylinder =π r² h = 6358
                              22/7 × r² × 28 = 6358
                              88 r² = 6358
                                   r²  = 6358 / 88
                                   r²  = 72.25
                                   r  =√72.25
                                   r = 8.5 cm
curved surface area of cylinder = 2πrh
                                                  = 2 × 22/7 × 8.5 × 28
                                                  = 1496 cm²