susheelh
If \(\frac{3}{7}\) of the students in a room are seniors and \(\frac{7}{25}\) of the other students are juniors, and there are \(x\) students in the room who are not juniors or seniors, how many students are in the room?
A. \(\frac{175}{72} x\)
B \(\frac{175}{51}x\)
C. \(\frac{25}{7}x\)
D. \(\frac{25}{3}x\)
E. \(10x\)
Let T = Total number of students in room
So, T = (
# of seniors) + (
# of juniors) + (
others)
3/7 of the students in a room are seniorsSo, the
# of seniors = (3/7)TIMPORTANT: We've already accounted for 3/7 of the students. So, 4/7 of the students are not yet accounted for. So, the number of remaining (unaccounted for) students =
(4/7)T 7/25 of the remaining students are juniorsSo,
# of juniors = (7/25)
(4/7)T=
(4/25)T There are x students in the room who are neither juniors nor seniorsSo,
# of others = xWe're now ready . . .
T = (
# of seniors) + (
# of juniors) + (
others)
T =
(3/7)T +
(4/25)T +
xGet common denominator: T =
(75/175)T +
(28/175)T +
xSimplify: T = (103/175)T + x
Subtract (103/175)T from both sides to get: (72/175)T = x
Multiply both sides by (175/72) to get: T = (175/72)x
Answer: A
Cheers,
Brent