Three taps A, B and C can fill a tank in 12, 15 and 20 hours respectively. If A is open all the time and B and C are open for one hour each alternately, the tank will be full in:

A certain numberof persons can complete a work in 34 days working 9 hours a day. If the number of persons is decreased by 40%, then how many hours a day should the remaining persons work to complete the work in 51 days?

The value of \({sin\theta+cos\theta-1\over sin\theta-cos\theta+1}\times\)\({ tan^2\theta(cosec^2\theta-1)\over sec\theta-tan\theta}\) is :

An article was sold at a profit of 12%. If the cost price would be 10% less and selling price would be Rs.5.75 more, there would be profit of 30%. Then at what price it should be sold to make profit of 20%.