2024 · Q22
A plank of wood 4.25 m long and 3.4 m wide is to be cut into square pieces of equal size. How many square pieces of largest size can be cut from the plank, if no wastage is allowed?
Elementary MathematicsHCF and LCM
- A45
- B90
- C400
- D500
Explanation
The plank measures 425 cm by 340 cm, so the largest square tile that leaves no wastage has side HCF(425, 340) = 85 cm. The number of such squares is (425/85) × (340/85) = 5 × 4 = 20, which is option (b) as printed in the paper. Note: the value 20 does not appear among the options as transcribed in this file (option (b) here reads 90). Note: this key is disputed — verify against the official UPSC key.