16. Form all possible common fraction from these numbers 3, 7, 8 and 15.
17. Compute.
1) 
2) 
18. Find
the value of 
if
1) z = 
2) z = 3,6
19. The radius of a circle is 3.6 cm. Find the diameter, circumference and the area of the circle. Round the answers to the tenths.
20. .
Find: 1) 6 % of 400
2) the
number 4 % of
which is 24
3) how
many per cent is 5 of 50?