Question

The diameters of two right circular cones are equal. If their slant heights are
in the ratio 5:4, then the ratio of their curved surface areas is:
(a) 4:5
(b) 25:16
(c) 5:4
(d) 1:1​

Answer 1

Answer:

c

Step-by-step explanation:

5:4 is correct answer

Answer 2

$Given \: the \: diameters \: of \: two \: right \\circular \: cones \: are \:equal .$

$Therefore , their \: radii \: equal$

$Let \: L \: and \: l \: are \: slant \: heights \: of \\the \: cones \: respectively.$

$\frac{L}{l} = 5 : 4 \: (given)\: ---(1)$

$Ratio \: of \: curved \: surface \:areas \\=\frac{\pi r L }{\pi r l } \\= \frac{ L}{l} \\= \frac{5}{4} \: [ From \: (1) ]$

Therefore.,

$\red {Ratio \: of \: curved \: surface \:areas} \green { = 5 : 4 }$

$Option \: \pink { ( c ) } \: is \: correct.$

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