Tiêu đề Refresher Exam 03 - Solution.pdf ✅

REFRESHER EXAM 03 APPLIED MATH – HPGE – PSAD ENGR. PAUL L. LADESMA CE | ME 1 | PPE 1. The time it takes to paint a house varies directly with the area of the walls and inversely with the number of painters. If 4 painters can paint a 2,400 square foot house in 6 hours, how long would it take 6 painters to paint a 3,600 square foot house? A. 6 hours B. 5 hours C. 4 hours D. 3 hours SOLUTION: Let: T = time A = area P = number of painters k = constant of proportionality Scenario 1: t1 = A1 P1 k Scenario 2: t2 = A2 P2 k Equate the two equations (k is constant): t1P1 A1 = t2P2 A2 (6 hour) (4 painters) (2400 ft2) = t2(6 painters) (3600 ft2) t2 = 6 hours Answer = 6 hours


REFRESHER EXAM 03 APPLIED MATH – HPGE – PSAD ENGR. PAUL L. LADESMA CE | ME 1 | PPE 4. In the system of equations below, c is a constant and x and y are variables. If the system of equations has no solution, what is the value of c? 2x − cy = 9 5x − 8y = 11 A. 16/5 B. -18/5 C. 18/5 D. 5/16 SOLUTION: Note: The linear equations will have no solution if the two lines are identical (same slope and intercept). Slope-intercept form: y = mx + b Equation 1: y = 2 c x − 9 c Equation 2: y = 5 8 x − 11 8 Equate the slopes: 2 c = 5 8 c = 16/5 Answer = 16/5