i have find this exercise in internet and try solve it but cant, pls help me.
1.Given A = 3.9 after rounding. Find the range of real value for A before rounding if A has been round to
(i) 1 decimal places.
(ii) 2 significant figures
2.If x = 2.0, y = 3.0 and z = 4.0, all are corrected to 1 decimal places, calculate the absolute and relative error for
(i) 2x + y
3.The position of nine trees which are to be planted a long the sides of a road, five on the north side and four on the south side.
If there are 3 figs, 4 prunes and 2 magnolias, find the number of different ways in which these could be planted assuming that the trees of the same species are identical.