A person completes a journey of 30 km at a speed of 6 km / h and a journey of the remaining 40 km at a speed of 8 km / h. What is his average speed of travel for the entire journey?

A work is done in 12 days by a team of 10 men, the same work is completed by a team of 10 women in 6 days. If both work together then in how many days the same work can be completed-

If 28 men complete the $$ {7\over 8}$$ portion of a work in a week, then how many man will have to work to complete the remaining work in one finish.

20 women complete a work in 16 days, 16 men complete the same work in 15 days, then what will be the ratio of the capacities of men and women?

Three numbers are in the ratio of 5: 6: 7. If the product of those numbers is 5670 then the largest number is-

The average of the three numbers is 60. The first number is one-fourth of the sum of the remaining two numbers, the first number is-

The average of 19 numbers is 24. If each number is multiplied by 3, what is the new average?

The average weight of 15 students of a class increases by 1.5 kg when a student of 40 kg is replaced by a new student. What is the weight (in kg) of the new student?