Question

From the table, answer the following question.
The percentage of decrease in speed during $19.00$ hrs and $21.00$ hrs is ____________.

Time(in hrs)	$5$	$7$	$9$	$11$	$13$	$17$	$15$	$19$	$21$
Speed (in km/hour)	$40$	$50$	$60$	$80$	$70$	$65$	$75$	$60$	$50$

• A. $16\frac{1}{3}\%$
• B. $16\frac{2}{3}\%$
• C. $17\frac{2}{3}\%$
• D. $18\frac{2}{3}\%$

Answer 1

The correct option is B $16\frac{2}{3}\%$

Decrease in speed between $19$ hrs and $21$ hrs $=60-50=10$ kmph

Initial speed $=60$ kmph

Percentage decrease $=$ $\frac{10}{60}\times 100$

$=16.66=16\frac{2}{3}\%$