byRituparna Nath Content Writer at Study Abroad Exams
Question: If x + 2y – 3z = 5 and 2x + 2y + 3z = 8, then 9x + 12y = ?
(A) 15
(B) 23
(C) 31
(D) 39
(E) It cannot be determined.
Correct Answer: D
Solution and Explanation
Approach Solution 1:
To find the solution for 9x + 12y = 3 * (3x + 4y). We need to eliminate z from the equation:
Let, x + 2y – 3z = 5 ... (1)
Let, 2x + 2y + 3z = 8 ... (2)
Adding both the equations we get, 3x + 4y = 13
3 * (3x + 4y) = 13 * 3 = 39
Hence the correct answer is D.
Approach Solution 2:
Equation 1 is x + 2y − 3z = 5.
Equation 2 is 2x + 2y + 3z = 8.
Solving Equations 1 and 2,
x + 2y − 3z = 5..
2x + 2y + 3z = 8
----------------
3x + 4y + 0 = 13
Now multiplying the resultant equation by 3 to get
9x + 12y = 39
Therefore,
9x + 12y = 39
Hence the correct answer is D.
Approach Solution 3:
(x + 2y – 3z = 5) + (2x + 2y + 3z = 8) => 3x + 4y = 13
Thus,
9x + 12y = 39
Hence the correct answer is D.
“If x + 2y – 3z = 5 and 2x + 2y + 3z = 8, then 9x + 12y = ?” - is a topic of the GMAT Quantitative reasoning section of GMAT. This question has been taken from the book “GMAT Official Guide Quantitative Review”. To solve GMAT Problem Solving questions a student must have knowledge about a good amount of qualitative skills. The GMAT Quant topic in the problem-solving part requires calculative mathematical problems that should be solved with proper mathematical knowledge.
Suggested GMAT Problem Solving Samples
- Metropolis Corporation has 4 Shareholders GMAT Problem Solving
- What is the number of integers from 1 to 1000, inclusive that are not divisible by 11 or by 35? GMAT Problem Solving
- If m is Three Times n, and if 2n + 3 is 20% of 25, What is the value of m? GMAT Problem Solving
- If Ben Were to Lose the Championship, Mike would be the Winner GMAT Problem Solving
- A Train Travelling at a Certain Constant Speed takes 30 seconds GMAT Problem Solving
- A circle with a radius R is inscribed into a square with a side K GMAT Problem Solving
- The square of \(5^\sqrt2)\ =? GMAT Problem Solving
- A farm has chickens, cows and sheep GMAT Problem Solving
- How many Terminating Zeroes does 200! Have? GMAT Problem Solving
- 1511−151014=? GMAT Problem Solving
- If g is an integer what is the value of(−1)g4−1(−1)g4−1? GMAT Problem Solving
- What is the Area of the Triangle with the following Vertices L(1,3) M(5,1) and N(3,5)? GMAT Problem Solving
- If P2−QR=10P2−QR=10 ,Q2+PR=10Q2+PR=10 ,R2+PQ=10R2+PQ=10 GMAT Problem Solving
- If 298=256L+N298=256L+N , Where L and N are Integers and 0≤N≤40≤N≤4 , What is the Value of N? GMAT Problem Solving
- How Many 5-Letter Words can be Formed Using the Letters of the English Alphabet that Contain 2 Different Vowels GMAT Problem Solving
- If a+b+c = 0 and a^3+b^3+c^3 = 216, What is the Value of a∗b∗c ? GMAT Problem Solving
- If a Polygon has 44 Diagonals, Then How Many Sides are There in the Polygon? GMAT Problem Solving
- If (a1 + a2 + a3 + .... +an) = 3(2n+1 - 2), For Every n≥1, Then a11 Equals GMAT Problem Solving
- A Chord of a Circle is Equal to its Radius. GMAT Problem Solving
- A Clock loses a Minute Every Three Hours for 4 Days and Gains 1% in the Subsequent 6 Days. GMAT Problem Solving
- A Container in the Shape of a Right Circular Cylinder is 1/2 Full of Water. GMAT Problem Solving
- How Many Multiples of 7 are there Between 21 and 343, Exclusive? GMAT Problem Solving
- If y (u-c) = 0 and j (u-k) = 0, Which of the Following Must be True, Assuming c < kc < k? GMAT Problem Solving
- What is the Remainder when 333^222 is Divided by 7? GMAT Problem Solving
- In a College of 300 Students, Every Student Reads 5 Newspapers and every Newspaper is Read by 60 Students GMAT Problem Solving
- If 4 People are Selected from a Group of 6 Married Couples, What is the Probability That none of Them would be Married GMAT Problem Solving
- If the Equation |x|+|y|= 5 Encloses a Certain Region on the Graph, What is the Area of that Region? GMAT Problem Solving
- If x = ¾ and y = ⅖ , What is the Value of √(x2+6x+9)(x2+6x+9) - √(y2−2y+1)(y2−2y+1)? GMAT Problem Solving
- A Cube Of Side 7 cm Is Coloured On Pair of Opposite Faces By Red, Green and Yellow Shades GMAT Problem Solving
- Given f(x) = x/(x + 1), For What Value k Does f(f(k)) = 2/3 ? GMAT Problem Solving
- Which of the Following Expressions CANNOT have a Negative Value? GMAT Problem Solving
- The Figure Shown Above Consists of a Shaded 9-Sided Polygon GMAT Problem Solving
- A list of measurements in increasing order is 4, 5, 6, 8, 10 and x GMAT Problem Solving
- Rahul Can Finish a Job in 30 Days GMAT Problem Solving
- The Price of Raw Materials Has Gone up by 15% GMAT Problem Solving
- In a Class of 100 Students 70 Passed in Physics, 62 Passed in Mathematics, GMAT Problem Solving
- If x and y Are Positive Odd Integers, And Both Numbers Have An Odd Number Of Positive Divisors GMAT Problem Solving
- Copper Pipe Costs x Cents Per Foot in 8-Foot Lengths GMAT Problem Solving
- Find The Smallest Positive 4-Digit Number Which, When Increased by 8, is Divisible by 12, 18, 30, and 45 GMAT Problem Solving
- How Much Pure Alcohol Should Be Added To 400 ml of a 15% Solution To Make The Strength Of The Solution 32%? GMAT Problem Solving
- If n = 3, What is The Value of 2^2n+1? GMAT Problem Solving
- The First Five Numbers in a Regular Sequence are 4, 10, 22, 46, and 94 GMAT Problem Solving
- The Volume of a Sphere With Radius r is (4/3)*pi*r^3 and the Surface Area is 4*pi*r^2 GMAT Problem Solving
- Which of the Following is Equal to 5^17×4^9? GMAT Problem Solving
- In a Shooting Competition, Probability of A Hitting Target is 2/5, by B is 2/3 and C is 3/5 GMAT Problem Solving
- The Sides of a Quadrilateral Taken in Order are 16,16,14 and 10 GMAT Problem Solving
- If 80 Lamps Can Be Lighted, 5 Hours Per Day For 10 Days GMAT Problem Solving
- If denotes the area of a circle with diameter d, then which of the following is equal to <4>*<6> GMAT Problem Solving
- If @ x=x^2/2x^2-2 , What is the Units Digit of @ (@4)? GMAT Problem Solving
- What is the product of all possible solutions of the equation |x+2|- 5|x+2| = -6? GMAT Problem Solving
Comments