Word Problem 7 (Work ,days and number of persons)
Problem 7: Working 8 hours a day, a work is done in 6 days. For how many hours a day the work is to be done, if it is to be finished in 4 days ?
a. 5 hours b. 10 hours c. 8 hours d. 16 hours
-math aptitude test-
This is a problem of inverse or indirect proportion. i-e one quantity increases while other decreases ! Here if we increase working hours per day, then number of working days decrease !
Here we suppose that ‘x’ hours a day are required to finish the work in 4 days !
Then we arrange this data as below – by putting arrows in different directions (because hours and days are inverse proportion);
We write fractions here in a way that tail term is nominator and head term is denominator and put an equal sign between two fractions !
Solving for ‘x’ we get;
So, work is to be done for 10 hours, so option ‘b’ is correct answer.