a$)(10$ marks$)$ A level was setup exactly at the middle distance between staffs A and $B$ that are

$70\mathrm{.}00$ meters apart. The reading for staff A was $1\mathrm{.}550$ meters and for staff B was $0\mathrm{.}930$

meters.

Then the level was moved and setup touching staff A $($i$.$e$.,$ the setup level is $0\mathrm{.}00$ meters

from staff A and $70\mathrm{.}00$ meters from staff $B).$ The reading of staff A was $1\mathrm{.}900$ meters and for

staff B was $1\mathrm{.}200$ meters $($staffs A and B were not moved during both settings$).$ What is the

error per meter for this level, if any?

b$)(10$ marks$)$ The level instrument used for the following measurements is perfectly calibrated.

A staff was placed on a bench mark $($BM$)20\mathrm{.}00$ meters from a perfectly setup level

instrument. The elevation of the BM equals $500\mathrm{.}000$ meters. The reading of the staff at this

BM was $0\mathrm{.}980$ meters. From this setup of the level instrument, a staff at point $Q,600\mathrm{.}00$

meters from the level instrument was read to be $2\mathrm{.}100$ meters. What is the elevation of

point Q$?$