Which of the following statement(s) given below is / are TRUE? A: A large solid cube is melted and casted into 3375 small cubes of side 1.6 cm, then side of large cube is 24 cm. B: Total surface area of a hemisphere of total volume 2425.5 cm3 is 693 cm2. C: Height of a cylinder of radius 14 cm and total surface area 2288 cm is 12 cm2.
Which of the following statement(s) given below is / are TRUE? A: A large solid cube is melted and casted into 3375 small cubes of side 1.6 cm, then side of large cube is 24 cm. B: Total surface area of a hemisphere of total volume 2425.5 cm3 is 693 cm2. C: Height of a cylinder of radius 14 cm and total surface area 2288 cm is 12 cm2. Correct Answer A and C
GIVEN:
Three statements.
CONCEPT:
Mensuration
FORMULA USED:
Volume of cube = S3
Total volume of hemisphere = (2 / 3)πR3
Total surface area of hemisphere = 3πR2
Total surface area of cylinder = 2πR(H + R)
CALCULATION:
A:
Volume of large solid cube = 3375 × Volume of a small cube
a3 = 3375 × 1.63
⇒ a3 = 13824
⇒ a = 24
Side of large cub = 24 cm
B:
Let radius of hemisphere = R
Total volume of hemisphere = (2 / 3) × (22 / 7) × R3 = 2425.5
R3 = 1157.625
⇒ R = 10.5
Total surface area of hemisphere = 3 × (22 / 7) × R2
= 3 × (22 / 7) × 10.52
= 1039.5 cm2
C:
Let height of cylinder = H
Total surface area = 2288
2 × (22 / 7) × 14 × (14 + H) = 2288
⇒ 14 + H = 26
⇒ H = 12
Height of cylinder = 12 cm
Hence, only statements A and C are TRUE.