Question

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

Answer 1

D)

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

`\sf (95)/(100)*x = 3.99`

`\sf x = (3.99*100)/(95)\\\\x = (399)/(95)\\\\\\x = 4.2 m`

Original length = 4.2 m