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Question
The length, breadth, and thickness of a rectangular sheet of metal are 4.234 m, 1.005 m, and 2.01 cm respectively. Give the area and volume of the sheet to correct significant figures.
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Solution
Given: Length of sheet, l = 4.234 m
Breadth of sheet, b = 1.005 m
Thickness of sheet, h = 2.01 cm = 0.0201 m
The given table lists the respective significant figures:
| Quantity | Number | Significant Figure |
| l | 4.234 | 4 |
| b | 1.005 | 4 |
| h | 0.0201 | 3 |
Hence, area and volume both must have the least significant figures, i.e., 3.
Area of the sheet = l × b
= 4.234 × 1.005
= 4.25517 m2
Volume of the sheet = l × b × h
= 4.234 × 1.005 × 0.0201
= 0.085528917 m3
After rounding off = 0.0855 m3
This number has only 3 significant figures, i.e., 8, 5, and 5.
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