The number of passengers on a certain bus at any given time is given by the equation P = 2(S 4)2 + 32, where P is the number of passengers and S is the number of stops the bus has made since beginning its route. If the bus begins its route with no passengers, what is the value of S when the bus has its greatest number of passengers?
9
6
4
2
1
no idea where to begin with ?
IMO: E For P to be maximum, S-4 will have to be minimum, which will happen at S=1 (because S can not be 0, since the bus started empty. And also, S being the number of stops, it can not be negative.)
The number of passengers on a certain bus at any given time is given by the equation P = -2(S - 4)2 + 32, where P is the number of passengers and S is the number of stops the bus has made since beginning its route. If the bus begins its route with no passengers, what is the value of S when the bus has its greatest number of passengers?
9
6
4
2
1
no idea where to begin with ?
is it -2(S-4)^2?? or -2(S-4) *2??
For the original equation answer will be 1 but if its -2(S-4)^2 then considering this, answer should be 4 Solution: -2(S-4)^2 becomes -2(4-4)^2 =0 and so P equals 32.
If we take any +ve number (S cannot be -ve) other than 4 then P will be less than 32. Lets consider S as 1 then P becomes -2(1-4)^2 +32 = -18+32 = 14.
Solution entirely based on assumption that -2(S-4)2 is actually -2(S-4)^2
The number of passengers on a certain bus at any given time is given by the equation P = 2(S 4)2 + 32, where P is the number of passengers and S is the number of stops the bus has made since beginning its route. If the bus begins its route with no passengers, what is the value of S when the bus has its greatest number of passengers?
9
6
4
2
1
no idea where to begin with ?
I will go with option C)4
P = -2(S-4)^2 + 32
S =0 P = 0 S =1 P = 14 S = 2 P = 24 S = 4 P = 32 S = 6 P = 24 S= 9 P = -ve
The number of passengers on a certain bus at any given time is given by the equation P = 2(S 4)2 + 32, where P is the number of passengers and S is the number of stops the bus has made since beginning its route. If the bus begins its route with no passengers, what is the value of S when the bus has its greatest number of passengers?
9
6
4
2
1
no idea where to begin with ?
A simple question where the answer can be found out by substituiting the value of S from the options given. The option that gives you the maximum value of P is the answer
@lakshya_iim_ahd ...... first , screw the question .....i love ur signature !!
@every1 ......now about the question.... how did u know that one has to place the value in the equation provided.? is it some rule that if u want to get a max. of one variable you somehow make the other variable end up in 0 ??? please throw some light on this guys !!
Now, this will maximize only when -ve part is zero.
@lakshya_iim_ahd ...... first , screw the question .....i love ur signature !!
@every1 ......now about the question.... how did u know that one has to place the value in the equation provided.? is it some rule that if u want to get a max. of one variable you somehow make the other variable end up in 0 ??? please throw some light on this guys !!
@lakshya_iim_ahd ...... first , screw the question .....i love ur signature !!
Well, thank you very much
aliz_khanz Says
@every1 ......now about the question.... how did u know that one has to place the value in the equation provided.? is it some rule that if u want to get a max. of one variable you somehow make the other variable end up in 0 ??? please throw some light on this guys !!
The answer to this is: If you see the equation, you notice two variables (P and S). The question says what is S when P is maximum and in the options, the values of S are given.
Now, you can either hack your brains to try find out the value of P and derive the correct value for S or else you solve backwards. You just put in the values of S (from the options given) and see for which value of S, your P is maximum.
guys, need some serious inputs urgently!! i have exactly one month to go for G-Day & I need some quality quant material to practise from. am done with OG-12...cud anybody suggest something more challenging given the fact that the quant in gmat has become tougher. looking forward to hearing from you!!
guys, cud anybody help me out with this along with the funda:
According to a survey, at least 70% of people like apples, at least 75% like bananas and at least 80% like cherries. What is the minimum percentage of people who like all three?
guys, cud anybody help me out with this along with the funda:
According to a survey, at least 70% of people like apples, at least 75% like bananas and at least 80% like cherries. What is the minimum percentage of people who like all three? A. 15% B. 20% C. 25% D. 0% E. 35%
cud u explain ur approach? i worked it out & the answer for me was 20%! amn ot sure, though!!
cheers
Given 70% like apple and 75% like banana (considering the least%) then the minimum % which likes both is 70% + 75% -100% =45%. Now adding 80% who like cherries we get 80% + 45% -100% =25%
guys, cud anybody help me out with this along with the funda:
According to a survey, at least 70% of people like apples, at least 75% like bananas and at least 80% like cherries. What is the minimum percentage of people who like all three?
A. 15% B. 20% C. 25% D. 0% E. 35%
Are there any ppl who don't take any of the fruits?Then in that case option D can also be an ans
guys, cud anybody help me out with this along with the funda:
According to a survey, at least 70% of people like apples, at least 75% like bananas and at least 80% like cherries. What is the minimum percentage of people who like all three?
A. 15% B. 20% C. 25% D. 0% E. 35%
IMO: C I solve these type of Qs using a graphical representation.
Step 1: Draw an axis. Consider vertical length as 100%.
Step 2: Take the highest percentage, and draw a vertical line from bottom to top. This line will cover 80% (from our Q).
Step 3: Take the next highest percentage value. This time draw a vertical line from top to bottom. Look at the figure closely. If only two percentages are given, answer will be the common area where both the two lines are in common. But since we have a third percentage, break the third line into parts such that it does not form a common area for all the three lines. If you look at the figure that I have attached here, this will make more sense.
Step 4: Answer to this question will be the area that is covered by all the three lines.
NOTE: This strategy is for deriving the minimum percentage for all the given percentages. Also, using this representation, it becomes relatively easier to crack for around 4-5 given percentages also.
How many diagonals does a 63-sided convex polygon have?
A. 3780 B. 1890 C. 3843 D. 3906 E. 1953
i guess option (B) will be the answer. the number of diagonals of any convex polygon(e.g.- square, pentagon...) can be found by using the formula nC2 - n, where n = no. of sides of the polygon.
How many diagonals does a 63-sided convex polygon have?
A. 3780 B. 1890 C. 3843 D. 3906 E. 1953
Ans should indeed be B. An extension of nC2 - n formula is that from any vertex of the poygon there are n-3 other vertices to form a diagonal . Hence, total no of diagonals is n(n-3) / 2 which is same as nC2 - n ...
In the xy-plane, the point (-2, -3) is the center of a circle. The point (-2, 1) lies inside the circle and the point (4, -3) lies outside the circle. If the radius r of the circle is an integer, then r = A. 6 B. 5 C. 4 D. 3 E. 2.
In the xy-plane, the point (-2, -3) is the center of a circle. The point (-2, 1) lies inside the circle and the point (4, -3) lies outside the circle. If the radius r of the circle is an integer, then r = A. 6 B. 5 C. 4 D. 3 E. 2.
