1. k and t are integers and k²-t² is an odd integer, which of the following must be an even integer ? .
A. k+t+1
B. k²+2kt+t²
C. k²+t²
A. k+t+1
B. k²+2kt+t²
C. k²+t²
2.In the xy-coordinate system, if (a,b) and (a+3, b+k) are two points on the line defined by the equation x = 3y-7, then k=
A. 9
B. 3
C. 7/3
D. 1
E. 1/3
A. 9
B. 3
C. 7/3
D. 1
E. 1/3
3. Peter and Paul start simultaneously on 2 different cars from Point A and travel towards Point B at speeds of 52 kmph and 39 kmph respectively on the same road. As soon as Peter reaches Point B, he returns back to Point A on the same road and meets Paul on the way. How far from Point B do the two friends meet, if the distance between the 2 points is 70 kms?
4. In triangle ABC, AD is the bisector of |A, AB=10 cm, AC=14 cm and area of triangle ABD = 140 sq cm. Find area of triangle ACD
5. rate of a certain chemical reaction is directly proportional to the square of the concentration of chemical A and inversely proportional to the concentration of chemical B present. If the concentration of chemical B is increased by 100%, which one of the following is the closest to the percentage change in the concentration of chemical A required to keep the reaction rate unchanged?
A. 100% decrease
B. 50% decrease
C. 40% decrease
D. 40% increase
E. 50% increase
A. 100% decrease
B. 50% decrease
C. 40% decrease
D. 40% increase
E. 50% increase