How many odd integers are there between 101 and 999 have distinct digits?
1 answer:
Every number will have only 3 digits. In the ones place, there are 5 choices. For every choice of digit made in the ones place, there are 8 possible choices for the hundreds place (you can choose from 1-9, omitting whatever is used in the ones place), and there are 8 possible choices for the tens place (you can choose from 0-9, omitting whatever has already been used elsewhere).
So there are
such numbers.
So there are
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Answer:
One watering system requires 36 minutes to complete the job alone while another watering system requires 12 minutes to complete the job alone.
Step-by-step explanation:
Given:
Both the system can complete the job = 9 minutes
We need find the time required by each system to do the job.
Solution:
Let the time required by another watering system to complete the job be 'x' mins.
Now given:
One watering system needs about three times as long to complete a job as another watering system.
Time required by one watering system =
Rate to complete the job by another watering system =
Rate to complete the job by One watering system =
Rate at which both can complete the job =
So we can say that;
Rate at which both can complete the job is equal to sum of Rate to complete the job by another watering system and Rate to complete the job by One watering system.
framing in equation form we get;
Now taking LCM to make the denominator common we get;
By Cross multiplication we get;
Dividing both side by 3 we get;
Time required by One watering system =
Hence One watering system requires 36 minutes to complete the job alone while another watering system requires 12 minutes to complete the job alone.