Bunuel
Lou has three daughters: Wen, Mildred, and Tyla. Three years ago, when Lou was twice as old as Tyla, he was 30 years older than Mildred. Now, he is 47 years older than Wen. In 4 years, Wen will be half as old as Tyla. What is the sum of the current ages of Lou and his three daughters?
(A) 138
(B) 144
(C) 154
(D) 166
(E) 181
We can create the equations, letting L, W, M, and T = the current ages of Lou, Wen, Mildren, and Tyla, respectively:
L - 3 = 2(T - 3)
L - 3 = 2T - 6
L = 2T - 3 → Eq. 1
and
L - 3 = 30 + M - 3
L = 30 + M
L - 30 = M → Eq. 2
and
L = 47 + W → Eq. 3
and
W + 4 = ½(T + 4)
2W + 8 = T + 4
2W + 4 = T → Eq. 4
Substituting 2W + 4 for T in Eq. 1, we have:
L = 2(2W + 4) - 3
L = 4W + 8 - 3
L = 4W + 5
Substituting 4W - 5 for L in Eq. 3, we have:
4W + 5 = 47 + W
3W = 42
W = 14
So T = 2W + 4 = 2(14) + 4 = 32
L = 4W + 5 = 4(14) + 5 = 61
M = L - 30 = 61 - 30 = 31
Thus, the sum of the current ages of the 4 people is 14 + 32 + 61 + 31 = 138.
Answer: A