Final Answer:
When scaling up the ratio on the left, The correct answer is c 60 hours.
Step-by-step explanation:
When scaling up the ratio on the left, the relationship between the quantities remains the same. In this case, if we increase the ratio of 20 hours on the left, the corresponding increase on the right will be proportional. The given options are multiples of 20, and to find the unknown quantity, we need to select the option that represents the scaled-up value.
To calculate this, we can set up a proportion:
20 hours / x = scaled ratio on the left / scaled unknown quantity on the right
Cross-multiplying gives:
20 hours * scaled unknown quantity on the right = scaled ratio on the left * x
Solving for x (the unknown quantity on the right):
x = (scaled ratio on the left * 20 hours) / scaled unknown quantity on the right
Substituting the given options, we find that x = 20 hours * 3 / 1 = 60 hours. Therefore, the correct answer is option c. 60 hours.
In summary, scaling up the ratio on the left by a factor of 3 results in the unknown quantity on the right being 60 hours. This approach is based on the principle of maintaining proportionality when scaling up or down in a ratio.