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?

The mean of the first 7 prime numbers is:

A family has two grandparents, two parents and four children. Two years ago, the average age of grandparents was 72 years. A year ago, the average age of parents was 36 years. Currently, the average age of children is 12 years. What is the current average age of the family?

A, B, C and D have to share the profit in the ratio of 4: 8: 11: 15. If there is a difference of Rs 22,000 between the minimum and maximum ratios, what is the sum of the other two ratios?

The ratio of the speeds of the two airplanes is 7:15. If the first airplane covers a distance of 1050 km in 3 hours, what is the speed of the second airplane?

If 0.8 : X  :: 5 : 8 then X is equal to

The ratio between the volume (cm³) of a cylinder and the curved surface area (cm²) is numerically 14: 1. If the height of the cylinder is 50 cm, what is the volume of the cylinder (cm³) ?

If the selling price of a product is multiplied by 2, the resulting profit is 6 times the original profit. What is the original profit percentage?