An office opens at 10 am and closes at 5 pm. The lunch break is of 30 minutes. What is the ratio of lunch break and total office hours?

What is the difference between 0.6 and 0.6%?

Simplify : 

A gun is fired at a distance of 1.7 km from Ram and he hears the sound after 25 seconds. The speed of sound in meter per second is

In a college 12% of all the students are interested in sports, 10% of the total students are interested in singing and three-fourth of the total students are interested in dancing and remaining 15 students are not interested in any activity, How many total students are there in the college?

A certain number of men can complete a work in 17 days working 8 hour a day. If the number of people is decreased to 60%. Then, find in how many hrs in a day should the remaining people work to complete the work in 51/2 days?

Simplify  .