Question

Janet can make 1/2 of a necklace in 20 minutes. At this rate, how many necklaces can Janet make in 2 hours?

Answer 1

3 necklaces

Explanation:

2 hours = 120 minutes

1 necklace in 40 minutes

120/40 = 3

3 necklaces

Answer 2

3 necklaces

Explanation:

2 hours needs to be in the same units as the 20 minutes

2 hours = 2 * 60 minute = 120 minutes

Now we can use ratios to solve

1/2 necklace x necklaces

-------------------- = ----------------

20 minutes 120 minutes

Using cross products

1/2 * 120 = 20x

60 = 20x

Divide by 20

60/20 = 20x/20

3= x