For what value of k are the points (2, −5), (6, −4) and (18, k) collinear?
Solution
Slope through the first two points = 14.
The third point must have the same slope from (2, −5): (k − −5)/(18 − 2) = 14.
k = −1.
24 questions, 16 of them short answer (type the number, as in IPMAT Indore). Each is marked with the exam level it suits. Answer, then open the step-by-step solution.
For what value of k are the points (2, −5), (6, −4) and (18, k) collinear?
Slope through the first two points = 14.
The third point must have the same slope from (2, −5): (k − −5)/(18 − 2) = 14.
k = −1.
Find the perpendicular distance of the point (0, 0) from the line 6x + 8y − 40 = 0.
Distance = |a x0 + b y0 + c|/√(a2 + b2) = |6(0) + 8(0) − 40|/√(36 + 64).
= |−40|/10 = 4.
Find the distance between the points (2, 0) and (6, 3).
√((6 − 2)2 + (3 − 0)2) = √(16 + 9) = 5.
Find the radius of the circle x2 + y2 − 8x + 12y + 16 = 0.
Complete the squares: (x − 4)2 + (y + 6)2 = 16 + 36 − 16 = 36.
Radius = √36 = 6.
The lines 3x + y = 18 and x − y = −2 meet at (h, k). Find h + k.
Solving the two equations gives x = 4 and y = 6.
h + k = 10.
Find the radius of the circle x2 + y2 − 2x + 4y + 1 = 0.
Complete the squares: (x − 1)2 + (y + 2)2 = 1 + 4 − 1 = 4.
Radius = √4 = 2.
Find the perpendicular distance of the point (1, 2) from the line 3x + 4y + 1 = 0.
Distance = |a x0 + b y0 + c|/√(a2 + b2) = |3(1) + 4(2) + 1|/√(9 + 16).
= |12|/5 = 2.
Find the perpendicular distance of the point (−1, −4) from the line 4x + 3y − 21 = 0.
Distance = |a x0 + b y0 + c|/√(a2 + b2) = |4(−1) + 3(−4) − 21|/√(16 + 9).
= |−37|/5 = 1.
Find the distance between the points (−1, −3) and (11, −12).
√((11 − −1)2 + (−12 − −3)2) = √(144 + 81) = 15.
Find the area of the triangle with vertices (6, −6), (−5, 4) and (−1, 7).
Area = (12)|x1(y2 − y3) + x2(y3 − y1) + x3(y1 − y2)|.
= (12)|6(−3) + −5(13) + −1(−10)| = 36.5.
Find the radius of the circle x2 + y2 + 4x + 6y − 3 = 0.
Complete the squares: (x + 2)2 + (y + 3)2 = 4 + 9 + 3 = 16.
Radius = √16 = 4.
Find the area of the triangle with vertices (−2, 3), (−6, 1) and (−4, 7).
Area = (12)|x1(y2 − y3) + x2(y3 − y1) + x3(y1 − y2)|.
= (12)|−2(−6) + −6(4) + −4(2)| = 10.
Find the distance between the points (−4, 4) and (−11, −20).
√((−11 − −4)2 + (−20 − 4)2) = √(49 + 576) = 25.
For what value of k are the points (0, 3), (4, 7) and (−8, k) collinear?
Slope through the first two points = 1.
The third point must have the same slope from (0, 3): (k − 3)/(−8 − 0) = 1.
k = −5.
Find the area of the region enclosed by |x| + |y| = 6.
The curve is a square with vertices (±6, 0) and (0, ±6); its diagonals are 12 each.
Area = (12) × 12 × 12 = 72.
The lines 2x + 4y = 30 and 2x − 4y = −2 meet at (h, k). Find h + k.
Solving the two equations gives x = 7 and y = 4.
h + k = 11.
Find the area of the triangle formed by the line x + 4y = 8 and the coordinate axes.
x-intercept = 81 = 8; y-intercept = 84 = 2.
Area = (12) × 8 × 2 = 8.
Find the area of the triangle formed by the line 2x + 5y = 10 and the coordinate axes.
x-intercept = 102 = 5; y-intercept = 105 = 2.
Area = (12) × 5 × 2 = 5.
Find the area of the triangle formed by the line x + 2y = 10 and the coordinate axes.
x-intercept = 101 = 10; y-intercept = 102 = 5.
Area = (12) × 10 × 5 = 25.
For what value of k are the points (2, 3), (4, 5) and (0, k) collinear?
Slope through the first two points = 1.
The third point must have the same slope from (2, 3): (k − 3)/(0 − 2) = 1.
k = 1.
The lines x − y = 6 and 5x + 2y = 23 meet at (h, k). Find h + k.
Solving the two equations gives x = 5 and y = −1.
h + k = 4.
Find the area of the region enclosed by 6|x| + |y| = 6.
The vertices are (±1, 0) and (0, ±6): a rhombus.
Area = (12) × 2 × 12 = 12.
Find the area of the triangle with vertices (7, −4), (−4, 6) and (7, −3).
Area = (12)|x1(y2 − y3) + x2(y3 − y1) + x3(y1 − y2)|.
= (12)|7(9) + −4(1) + 7(−10)| = 5.5.
Find the area of the region enclosed by |x| + |y| = 4.
The curve is a square with vertices (±4, 0) and (0, ±4); its diagonals are 8 each.
Area = (12) × 8 × 8 = 32.
These are original practice questions written by Target Campus in the pattern, syllabus and difficulty of IPMAT Indore, IPMAT Rohtak, JIPMAT, NPAT and SET. They are not previous-year papers.