Physics Help please!!!!! (elevator, N, Gravity, Force)

Two blocks each of mass m = 3.30 kg are fastened to the top of an elevator as in the figure below.
(a) If the elevator accelerates upward at 1.6 m/s2, find the tensions T1 and T2 in the upper and lower strings.

T1_______ N
T2________N


figure: http://www.webassign.net/sercp8/p4-21a.gif

The upper string supports the weight of both masses plus provides additional force to accelerate them upward. The lower string does the same but for the lower mass only
T1 = (m1 + m2) (g + a) = (6.6) ( 9.8 + 1.6) = 75.2 N
T2 = half of T1 = 37.6 N

we will write newton's second laws for each of the masses, I will call the upper mass 1 and the lower mass 2

the forceson the lower mass are the tension in string 2 acting up, the weight down, and these must combine to produce an ma term where a=1.6m/s/s

so we have

T2-m2g = m2a = 1.6m2

for the upper mass T1 pulls up, T2 and m1 g act down:

T1 - m1g - T2= 1.6m1

from the first equation we know that T2=m2(g+1.6)

sub into the T1 equation:

T1- m1g -m2(g+1.6)=1.6m1

you know m1 =m2=3.3, g=9.8, solve for T1, then for T2