New Enroll in RBI Grade B New Batch - Starts on May 21

    Question

    The radii of two solid right circular cylinders are 6 cm

    and 4 cm respectively and their heights are (h+1) cm and (2h+1) cm respectively. If the areas of the whole surface of the two cylinders are equal, then the ratio of their volumes is:
    A 17:13 Correct Answer Incorrect Answer
    B 13:13 Correct Answer Incorrect Answer
    C 23:27 Correct Answer Incorrect Answer
    D 19:17 Correct Answer Incorrect Answer
    E 27:23 Correct Answer Incorrect Answer

    Solution

    Whole surface area of cylinder = 2πR(H+R) 2π x 6[h+1+6] = 2π x 4[2h+1+4] 6[h+7] = 4[2h+5] 6h+42 = 8h+20 2h = 22 h = 11 so, V1/V2 = (π x 62x (h+1))/(π x 42x (2h+1)) = (36 x (11+1))/(16 x (2x11+1)) = (36 x 12)/(16 x 23) = 27/23

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