For the following questions answer them individually
A boatman rows 15 km in 15 minutes, along the stream and 10 km in 1 hour against the stream. Find the speed of the boat in still water.
If (x + y) : (y + z) : (z + x) = 3 : 5 and (x + y + z) = 45, then what is the value of z?
A and B together can complete a given work in 10 days. C can complete the same work alone in 15 days. In how many days can they complete the work, if all three work together?
Rima buys a chair for Rs. 1000 and sells it at a loss of 8%. What is the selling price of the chair?
The following table shows the number of girls and boys in different classes. Find the sum of total number of students in the class.
Find the value of $$\left[7 + \left\{4 \times \left(2 + 5 \times 4 \right)\right\}\right]$$.
What will be the ratio of simple interest earned by certain amount at the same rate of interest for 8 years and 20 years?
A trader marks his goods at 55% above the cost price and allows a discount of 20%. What is his gain percentage?