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A student measured the length of a room and obtained the measurement of 3.99m. If the percentage error of his
measurement was 5% and his own measurement was smaller than the length, what is the length of the room?
A. 3.78m B. 3.80m C. 4.18m D. 4.20m

Respuesta :

devishri1977

Answer:

D)

Step-by-step explanation:

Percentage word problems:

Let the original length be 'x'.

Percentage error = 5 %

So, (100 -5)% = 95% of the original measurement is 3.99 m

     95% of x = 3.99

     [tex]\sf \dfrac{95}{100}*x = 3.99[/tex]

              [tex]\sf x = \dfrac{3.99*100}{95}\\\\x = \dfrac{399}{95}\\\\\\x = 4.2 m[/tex]

Original length = 4.2 m