If every side of a cube is increased by 25%, then what will be percentage increase in the surface area -
Answer & explanation
Correct answer: option 1
Side of a cube = a
Surface area (S.A.) of cube = 6a2
25% = \(\frac{1}{4}\)
ATQ,
Actual : New
side ⇒ 4 : 5 (a : b)
S.A. ⇒ 6a2 : 6b2
⇒ a2 : b2
⇒ 42 : 52
⇒ 16 : 25
Increased in surface area = 25 - 16 = 9
Increased percentage = \(\frac{9}{16}\) × 100 = 56.25%