snakedoc wrote:1) In the xy plane, at what point does y = (x + a)(x + b) cross the x axis?
a. a + b = -1
b. graph intersects y axis at (0, -6)

snakedoc wrote:2) S is finite set of numbers. Does S contain more negative numbers than positive numbers?
a. Product of all numbers in S is -1200
b. There are 6 numbers in S

snakedoc wrote:1)
5) Sum of positive integers x and y is 72. What is xy?
a. x = y + 1
b. x and y have same tens digit

Anurag@Gurome wrote:

snakedoc wrote:5) Sum of positive integers x and y is 72. What is xy?
a. x = y + 1
b. x and y have same tens digit

x + y = 77

(1) x = y + 1.
We have two equations and two variables, so we can solve them x and y, hence we can find xy; SUFFICIENT.

(2) x and y have same tens digit.
The tens digit should be 3 because if it is 2, then maximum possible sum can be 58 and if it is 4, then minimum possible sum will be 80.
The sum of x and y is 77, so the sum of unit places is 17 and it is possible only with the digits 8 and 9, as 9 + 8 = 17
So, the numbers are 38 and 39; SUFFICIENT.

The correct answer is D.

snakedoc wrote: 4) The ratio of women to children on a tour is 5:2. How many men are there?
a. Ratio of children to women is 5:11
b. There are less than 30 women on the tour.

rijul007 wrote:

snakedoc wrote:1) In the xy plane, at what point does y = (x + a)(x + b) cross the x axis?
a. a + b = -1
b. graph intersects y axis at (0, -6)

y = (x + a)(x + b)
y = x^2 + x(a+b) + ab
x^2 + x(a+b) +ab = 0
for x- intercept
put y=0


a. a + b = -1
x^2 - x + ab = 0

value of x depends on ab

Insufficient



b. graph intersects y axis at (0, -6)

y = (x+a)(x+b)
at y intercept, x=0

y = ab = -6


Combining the two statements

x^2 +x(a+b) + ab = 0
x^2 - x - 6 = 0
(x-3)(x+2) = 0

y= (x+a)(x+b) crosses x-axis at (3,0) and (-2,0)

Option C

pemdas wrote:agree about (-3;2) and x-intercepts but disagree about answer C
Need to find only one possible point at which the graph intercepts x axis ...

Anurag@Gurome wrote:

snakedoc wrote:5) Sum of positive integers x and y is 72. What is xy?
a. x = y + 1
b. x and y have same tens digit

The correct question says that x + y = 77 (if the sum is 72 then either x and y are both odd, or x and y are both even. According to statement 1, if one of them is odd, the other one will be even, which is a contradiction). So, I have done the question, assuming x + y = 77.

(1) x = y + 1.
We have two equations and two variables, so we can solve them x and y, hence we can find xy; SUFFICIENT.

(2) x and y have same tens digit.
The tens digit should be 3 because if it is 2, then maximum possible sum can be 58 and if it is 4, then minimum possible sum will be 80.
The sum of x and y is 77, so the sum of unit places is 17 and it is possible only with the digits 8 and 9, as 9 + 8 = 17
So, the numbers are 38 and 39; SUFFICIENT.

The correct answer is D.

pemdas wrote:@Anurag, you're assuming the sum of two positive integers in your solution?

question stem -> ax+by=72 implies x+x+...+x+y+...y=72 and a,b must be whole numbers, as we are suggested about the (number) of integers; it would be not correct mathematically to state 2.5 or 2.4 integers. Hence a,b are integers.
st(1) x=y+1 implies a(y+1)+by=72
when y is odd, x is even and vice verse, x and y can be any values depending on a,b Not Sufficient
st(2) x,y=T(U,u). The smallest ten's digit possible for the two-digit numbers is 10. Many variations are present with st(2), bifurcated -> x=10, y=13, a=3,b=4 OR x=17,y=19, a=2,b=2 Not Sufficient
Combined st(1&2): a(y+1)+by=72 considered with the condition x,y=T(U,u)
x=11, y=10
a=2, b=5 -> 2(10+1)+5*10=72

x=15, y=14
a=2, b=3 -> 2(14+1)+3*14=72

xy=15*14 and xy=11*10 Not Sufficient

e

Anurag@Gurome wrote:

snakedoc wrote:5) Sum of positive integers x and y is 72. What is xy?
a. x = y + 1
b. x and y have same tens digit

The correct question says that x + y = 77 (if the sum is 72 then either x and y are both odd, or x and y are both even. According to statement 1, if one of them is odd, the other one will be even, which is a contradiction). So, I have done the question, assuming x + y = 77.

(1) x = y + 1.
We have two equations and two variables, so we can solve them x and y, hence we can find xy; SUFFICIENT.

(2) x and y have same tens digit.
The tens digit should be 3 because if it is 2, then maximum possible sum can be 58 and if it is 4, then minimum possible sum will be 80.
The sum of x and y is 77, so the sum of unit places is 17 and it is possible only with the digits 8 and 9, as 9 + 8 = 17
So, the numbers are 38 and 39; SUFFICIENT.

The correct answer is D.