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If each side of a cube is decreased by 19%, then decrease in surface area is

A) 40%
B) 38.40%
C) 35%
D) 34.39%

Correct Answer:




D) 34.39%

Description for Correct answer:

Here, x = y = -19%

According to the formula,

Percentage decrease in surface area

= \( \Large \left[ x + y + \frac{xy}{100} \right] \)%

= \( \Large \left[ -19 - 19 = \frac{ \left(-19\right) \times \left(-19\right) }{100} \right] \)%

= \( \Large \left[ -38 + \frac{361}{100} \right] \)%

= \( \Large \left[-38 + 3.61 \right] \% \) = - 34.39%

Part of solved Volume and surface area questions and answers : >> Elementary Mathematics >> Volume and surface area

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