SOLUTION: In the following figure:A B C D E F G H

Algebra.Com
Question 2252: In the following figure:A B C
D
E F G
H
I
Each of the digits 1, 2, 3, 4, 5, 6, 7, 8, and 9 is:
a)Represented by a different letter in the figure above.
b)Positioned in the figure above so that each of A + B + C,C + D +E,E + F + G, and G + H + I is equal to 13.
Which digit does E represent?

Answer by khwang(438)   (Show Source): You can put this solution on YOUR website!
Sol: By given condition, we have
A+B+C = 13...(1)
C+D+E = 13...(2)
E+F+G = 13...(3)
G+H+I = 13...(4)
Add up (1)+(2)+(3)+(4), we get
52=13*4 = A + B + C+ C + D + E+ E + F + G+ G + H + I = C+E+G+(A + B + C+ D +E + F + G + H + I)
= C+E+G+(1+2+ 3+ 4+ 5+ 6+ 7+ 8+ 9) = C+E+G+(1+9)*9/2 = C+E+G + 45

Hence,C+E+G = 52 - 45 = 7...(5)
By (5), we have E = 7-C-G <= 7-3 = 4 (since, the smallest C,G are 1 or 2)
By (2)-(5)., we get D-G = 6, or D = G+6...(6)
Since D,G are between 1 and 9,
so D= 7, 8,or 9, and we have G=1,2 or 3
By (3)-(5)., we get F-C = 6, or F = C+6...(7)
Since F,C are between 1 and 9,
so F= 7, 8,or 9, and we have C=1,2 or 3
By (6) ,(7) & (5):
Case(i) When G =1, D = G+6 =7,
and then C = 2, F = C+6=8, E = 7-C-G= 4
Or C = 3, F = 9, E = 3 (invalid,since the same C,E value)
Case(ii) When G =2, D = G+6= 8,
and then C = 1, F = C+6=7, E= 7-C-G=4
Or C = 3, F = 9, E = 2(invalid,since the same C,G value)
Case(iii) When G =3, D = G+6=9,
and then C = 1, F = C+6=7, E =7-C-G= 3(invalid,since the same E,G value)
Or C = 2, F = C+6=8, E=7-C-G = 2(invalid,since the same C,E value)
In these three possible cases of the values of G, we obtain that the only valid value of E is 4.

Kenny


RELATED QUESTIONS

In the following figure: A B C --------D --------E F G ------------H (answered by checkley71)
In the following addition problem, each letter represents one of the digits 0, 1, 2, 3, (answered by ikleyn,Edwin McCravy)
which of the following could be the units digit of 57^n where n is a positive integer?... (answered by richard1234)
Let U = {a, b, c, d, e, f, g, h, i, j, k, l, m, n}, L = {a, b, c, d, e, f, g} and S = {a, (answered by Edwin McCravy)
Consider the function F and G defined by F(x)={{{(x-6)/(2x+5)}}} and... (answered by solver91311)
The base 10 (decimal) number system has 10 different digits. The base 16 number system... (answered by Theo)
please help. i need answers. i have school tommorow and i need these by tommorow.pleasee. (answered by solver91311)
a b c d e f g h i j k l m n o p q r (answered by ewatrrr)
Let the universal set A = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12}, and the following... (answered by jim_thompson5910)