Hey Guys,
Can you please help me understand the solution to this problem?
A satellite is composed of 30 modular units, each of which is equipped with a set of sensors, some of which have been upgraded. Each unit contains the same number of non-upgraded sensors. If the number of non-upgraded sensors on one unit is 1/5 the total number of upgraded sensors on the entire satellite, what fraction of the sensors on the satellite have been upgraded?
A) 5/6
B) 1/5
C) 1/6
D) 1/7
E) 1/24
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Answer
The problem tells us that the satellite is composed of 30 modular units, and there are sensors on each unit. Each unit contains the same number of non-upgraded sensors. We can use n to represent the number of sensors per unit that have not been upgraded. The problem also discusses the total number of upgraded sensors on the entire satellite; we can use u to represent this figure. The problem asks for the fraction of upgraded sensors on the entire satellite, u, among all sensors on the entire satellite, 30n + u. In other words, we want to find the fraction .
The problem tells us that the number of non-upgraded sensors on one unit, n, is 1/5 of the total number of upgraded sensors on the entire satellite, u. We can write this as a proportion and simplify:
5n = u
We can substitute this relationship into our original fraction:
This corresponds to answer choice D.
Alternately, we might consider using Smart Numbers. However, since there is a constraint in the problem (the total number of units is 30) and a specific relationship between the numbers (the number of non-upgraded sensors on each unit is 1/5 the total upgraded sensors on the satellite), it would be difficult to select Smart Numbers that work well.
The correct answer is D
I don't understand where they came up with 30n + u.. When I do this I would assume that N+U=30....
Can you please help me understand the solution to this problem?
A satellite is composed of 30 modular units, each of which is equipped with a set of sensors, some of which have been upgraded. Each unit contains the same number of non-upgraded sensors. If the number of non-upgraded sensors on one unit is 1/5 the total number of upgraded sensors on the entire satellite, what fraction of the sensors on the satellite have been upgraded?
A) 5/6
B) 1/5
C) 1/6
D) 1/7
E) 1/24
-------------------------------
Answer
The problem tells us that the satellite is composed of 30 modular units, and there are sensors on each unit. Each unit contains the same number of non-upgraded sensors. We can use n to represent the number of sensors per unit that have not been upgraded. The problem also discusses the total number of upgraded sensors on the entire satellite; we can use u to represent this figure. The problem asks for the fraction of upgraded sensors on the entire satellite, u, among all sensors on the entire satellite, 30n + u. In other words, we want to find the fraction .
The problem tells us that the number of non-upgraded sensors on one unit, n, is 1/5 of the total number of upgraded sensors on the entire satellite, u. We can write this as a proportion and simplify:
5n = u
We can substitute this relationship into our original fraction:
This corresponds to answer choice D.
Alternately, we might consider using Smart Numbers. However, since there is a constraint in the problem (the total number of units is 30) and a specific relationship between the numbers (the number of non-upgraded sensors on each unit is 1/5 the total upgraded sensors on the satellite), it would be difficult to select Smart Numbers that work well.
The correct answer is D
I don't understand where they came up with 30n + u.. When I do this I would assume that N+U=30....
