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**[SOLVED] Carnot engine - please help asp**

I just typed a whole question and as I typed it I solved it, lol!

**1. Homework Statement**

In the 1st stage of a 2-stage Carnot engine, energy is absorbed as heat Q1 at temp T1, work W1 is done, and energy is expelled as heat Q2 at lower temp T2. The 2nd stage absorbs that energy as heat Q2, does work W2 and expels energy as heat Q3 at a still lower temp T3. Prove that the efficiency of the engine is (T1 - T3)/T1

Stage 1 Qin=Q1

Qex=Q2

T2 less then T1

W1

Stage 2 Qin=Q2

Qex=Q3

T3 less then T2

W2

**2. Homework Equations**

e =Qex/W = (Qin-Qex)/Qin = (Tin-Tex)/Tin

**3. The Attempt at a Solution**

e(stage1) = (T1-T2)/T1

e(stage1) = (T2-T3)/T2

How do you put them together?

**or**

is this all wrong? how do I approach this?