In an apartment building that has 490 units, 4 out of every 7 units are currently rented, including 1/5 of the one-bedroom units. If, of the rented apartments, there is a 6:1 ratio of two-bedroom units to one-bedroom units, and the building only consists of two-bedroom and one-bedroom units, how many two-bedroom units are not rented?
(A) 50
(B) 70
(C) 100
(D) 105
(E) 140
Rented = 4/7*490 = 280.
Rented two-bedroom = 6/7*280 = 240;
Rented one-bedroom = 1/7*280 = 40 (or 280-240=40).
Rented one-bedroom units are 1/5 of all one-bedroom: 1/5*{All one bedroom} = 40 --> {All one-bedroom} = 200.
{All two-bedroom} = 490 - 200 = 290.
Two-bedroom not rented = 290 - 240 = 50.
Answer: A.
(A) 50
(B) 70
(C) 100
(D) 105
(E) 140
Rented = 4/7*490 = 280.
Rented two-bedroom = 6/7*280 = 240;
Rented one-bedroom = 1/7*280 = 40 (or 280-240=40).
Rented one-bedroom units are 1/5 of all one-bedroom: 1/5*{All one bedroom} = 40 --> {All one-bedroom} = 200.
{All two-bedroom} = 490 - 200 = 290.
Two-bedroom not rented = 290 - 240 = 50.
Answer: A.