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The radius of the base and the height of a closed cylinder are in the ratio 1:3. Using π=722, find its total surface area if its curved surface area is 924 m2.
1512 m²
1848 m²
908 m²
1232 m²
1232 m²
Since the radius and height are in the ratio 1:3, let r=x and h=3x. Substitute directly into the CSA formula to solve for x, then calculate the Total Surface Area as TSA=CSA+2πr2.
Ratio of base radius to height of closed cylinder = 1:3, Curved Surface Area (CSA) = 924 m2, π=722
CSA=2πrh,TSA=2πr(r+h)
Since the radius and height are in the ratio 1:3, let r=x and h=3x. Substitute directly into the CSA formula to solve for x, then calculate the Total Surface Area as TSA=CSA+2πr2.
Confusing the total surface area formula by forgetting to add the area of the two circular bases (2πr2) to the curved surface area.
Step 1: Assume radius and height from the ratio
Given that the ratio of the radius (r) to the height (h) is 1:3, we can set r=x and h=3x for some positive constant x.
r=x,h=3x
Step 2: Use the Curved Surface Area (CSA) to find x
The formula for the curved surface area of a cylinder is CSA=2πrh. Substituting the values, we get 2×722×x×3x=924.
2×722×x×3x=924⟹7132x2=924
Step 3: Solve for x and determine dimensions