Question

Ammu was creating a floral rangoli for Onam. It took her 2 hours to finish it. If two of her cousins joined her to create another rangoli identical to the first, how much time will be required to complete it?

• A. 30 minutes
• B. 20 minutes
• C. 45 minutes
• D. 40 minutes

Answer 1

The correct option is D 40 minutes

If more people work together, the completion of the rangoli will take less time.

$\therefore$ This is a case of inverse proportion.
Ammu took 2 hours = 120 minutes to finish the rangoli.
Since two of her cousins joined her, now there are 3 people working on it.
Using the formula for inverse proportion,
$Numberofpeople\times Timerequired=constant$
$\Rightarrow 1\times 120=3\times Timerequired$
$\therefore Timerequired=\frac{1\times 120}{3}=40minutes$.