Question

how long can it swing?

	height dropped from (centimeters)	time swung (seconds)
test 1	10 cm	?
test 2	20 cm	49 sec
test 3	30 cm	72 sec

options: 85 sec, 65 sec, 25 sec, 55 sec

Explanation:

Step1: Analyze the trend

As the height dropped from increases (10 cm → 20 cm → 30 cm), the time swung also increases (we need to find for 10 cm, given 20 cm is 49 sec and 30 cm is 72 sec). The time for 10 cm should be less than 49 sec (since 10 < 20).

Step2: Evaluate options

• 85 sec: Greater than 49, invalid.
• 65 sec: Greater than 49, invalid.
• 25 sec: Less than 49, reasonable (since 10 cm is less than 20 cm, time should be less than 49).
• 55 sec: Greater than 49, invalid.

Answer:

25 sec