Mathematical Series Questions for Competitive Exams

A and B together can complete a work in 21 days. If A takes 42 days to complete the work alone, how many days will B take to complete the same work alone?

A and B take the responsibility of doing a work for Rs 250. A can do that work alone in 5 days and B alone in 15 days. They complete the work in 3 days with the help of C. If everyone gets paid in proportion to the work, then how much amount will C get?

A, B, and C alone can do a work in 40 days ,120 days and 36 days respectively. A and B work together for 20 days and leave it incomplete. C carries on the work and complete it alone.  How many days did C take to complete the work?

A can do $$ {4\over 5}$$ of a work in 20 days and B can do $$ {3\over 4}$$ of the same work in 15 days. They work together for 10 days. C alone completes the remaining work in 1 day.  B and C together can complete of $$ {3\over 4}$$ of the same work in:

A and B working together, can do a piece of work in $$ {4{1\over 2}}$$ hours. B and C working together can do it in 3 hours. C and A working together can do it in $$ {2{1\over 4}}$$ hours. All of them begin the work at the same time. Find how much time they will take to finish the piece of work?

A and B together can do a certain work in x days. Working alone, A and B can do the same work in (x+8) and (x+18) days, respectively. A and B together will complete $$ {5\over 6}$$ of the same work in;

Sudhir and Shyam can do a work in 12 days, while Shyam alone can complete it in 30 days. In how many days can Sudhir complete that work alone?

The ratio of two numbers is 5 : 11. If both numbers are increased by 10, the ratio becomes 7 : 13. What is the sum of the two numbers?

The ratio of the sides of a triangle is $$ {1\over2}$$: $$ {1\over3}$$: $$ {1\over4}$$ and its perimeter is 104 cm. is. What is the length of the longest arm?

The ratio of the students of one school is 3: 5 with the students of the other school, if in the first school there were 50 students more and in the second there were 80 students less then the ratio would be 5: 6. Find the total number of students in both schools.