20 men could complete a work in 80 days. They worked together for 60 days, after that due to bad whether the work is stopped for 10 days. How many more men should be employed so as to complete the work in time?

In the given figure, from the point P two tangents PA and PB are drawn to a circle with center O and radius 5 cm. From the point O, OC and OD are drawn parallel to PA and PB respectively. If the length of the chord AB is 5 cm. then what is the value (in degrees) of ∠COD?

Income of A and B are in ratio 3:4 and their expenditure are in ratio 4:7 their saving are equal if A save Rs 1760 more and B increase his expenditure by Rs 880 then their saving are in ratio 7:4 .find the average income of A and B?

5 men and 5 women earn Rs.600 in 3 days. 10 men and 20 women earn Rs. 3500 in 5 days. In how many days can 6 men and 4 women earn Rs. 1060?

12 men can do a work in X days. 20 women can do the same work in (X -1) days. 15 men can do the work in y days while 30 women can do it (Y- 2) days . Find the value of X. 

One boy from a group of eight boys left and a new boy with a weight of 56 kg joined the group, which resulted in an average weight of 2.5 kg has increased, what is the weight of the new boy?