Question 10
Two people could fit new windows in house in 3 days.
(i) One of the people fell ill before the work started.
How long would the job take now?
(ii) How many people would be needed to fit the windows in one day?
Answer:
(a) days (ii) 6persons (i) Let the number of days required by 1 man to
fit all the windows be x.
The following table is obtained.
Solution:
Lesser the number of people,
more will be the number of days required to fit all the windows.
Hence, this is a case of inverse proportion.
Therefore,
Hence, the number of days taken by 1 man to fit all the windows is 6.
(ii) Let the number of people required to fit all the windows in one day be y.
The following table is formed.
Lesser the number of days,
more will be the number of people required to fit all the windows.
Hence, this is a case of inverse proportion.
Therefore,
Hence, 6 people are required to fit all the windows in one day.
Question 11
A school has 8 periods a day each of 45 minutes duration.
How long would each period be, if the school has 9 periods a day,
Assuming the number of school hours to be the same?
Answer:
40 minutes
Solution:
Let the duration of each period,
When there are 9 periods a day in the school,
Be x minutes.
The following table is obtained.