I guess this is one of those questions which looks simple but very easy to get wrong. First of all, I got the question wrong too. I thought the answer is $37.8. But the correct amount is 38.50$ The amount spent by the farmer on chicken is 0.4*35 = 14$ Since he got 20% off, 14$ is only 80% of the ful...

Top line X X X X Bottom Line Y Y Y Y Y To form a triangle you have choose 2 Xs and 1 Y or 2 Ys and 1X. 2Xs can be chosen in 4C2/2! = 4!/2!2! = 6 1 Y can be chosen in 5C1 = 5 ways So 2Xs and 1 Y can be chosen in 30 ways. Similarly, 2Ys and 1 X can be chosen in 5!/3!2! * 4 = 40 So total = 30 + 40 = 70...