Three quantities X, Y and Z are such that XY=kZ where k is constant. Initially, X was at 4 and X:Y:Z was 2:3:4. If the value of Y is changed to 12 and Z is kept constant, find the value of X.

Three quantities X, Y and Z are such that XY=kZ where k is constant. Initially, X was at 4 and X:Y:Z was 2:3:4. If the value of Y is changed to 12 and Z is kept constant, find the value of X.

A. 2
B. 3
C. 5
D. 6
X:Y:Z=2:3:4
X=4
Then, Y=6, Z=8 XY=kZ 4*6=k*8 8k=24 k=3
Y=12, Z=8
X*12=3*8
X=2

The plan for a rectangular area is drawn to a scale of 1:500. If the length and breadth in the plan is 30 cm and 20 cm, find the actual area.

The plan for a rectangular area is drawn to a scale of 1:500. If the length and breadth in the plan is 30 cm and 20 cm, find the actual area.

A. 1200 m²
B. 1500 m²
C. 12000 m²
D. 15000 m²
Actual length
= 30*500 cm Actual breadth
= 20*500 cm Actual area
= 30*20*500*500 = 15000 m²

In what ratio should the profit of Rs.8000 be divided if X starts a business with an investment of Rs. 20000, Y invests Rs.7500 for 4 months and Z invests Rs.15000 after 3 months from the start of the business.

In what ratio should the profit of Rs.8000 be divided if X starts a business with an investment of Rs. 20000, Y invests Rs.7500 for 4 months and Z invests Rs.15000 after 3 months from the start of the business.

A. 16 : 2 : 3
B. 8 : 3 : 6
C. 16 : 2 : 9
D. 6 : 9 : 1
Let the profit of X be P1, that of Y be P2 and of Z be P3.
P1:P2:P3 = 20000*12 : 7500*4 : 15000*9 = 240 : 30 : 135 = 80 : 10 : 45
= 16 : 2 : 9

The ratio of boys and girls in a class was 11:13. 8 girls and 4 boys join the class from this academic year and the ratio becomes 4:5. Find the strength of the class.

The ratio of boys and girls in a class was 11:13. 8 girls and 4 boys join the class from this academic year and the ratio becomes 4:5. Find the strength of the class.

A. 96
B. 68
C. 72
D. 108
Let the number of boys and girls in the class be 11x and 13x. 4 boys and 8 girls join the class. Strength of the class
= 11x+13x+4+8
= 24x+12 (11x+4):(13x+8) = 4:5 5*(11x+4)=4*(13x+8) 55x+20=52x+32 3x=12 x=4 24x+12=108