Ratio and Proportion

A. 18
B. 15
C. 12
D. 5
2x/25 = 6/(x/3) 2x/25 = 18/x 2x*x = 18*25 x² = 9*25 x=3*5 x=15

A. 1:2
B. 3:5
C. 1:3
D. 3:4
72 should be divisible by addition of the above ratio.
Using trial and error method
For (a): – 1+2 = 3, 72 is divisible by 3
For (b): – 3+5 = 8, 72 is divisible by 8
For (a): – 1+3 = 4, 72 is divisible by 4
For (a): – 3+4 = 7, 72 is not divisible by 7
Therefore, the answer is option (d)

A. 2:3
B. 3:2
C. 3:4
D. 4:3
x+y = 750 y-x = 150 Solving,
y = 450
x = 300 x:y = 300:450 = 2:3

A. 3:2
B. 1:2
C. 1:5
D. 2:1
p = q+(50/100)q = 1.5q p:q = 1.5q:q = 1.5:1 = 3:2

A. 8
B. 6
C. 12
D. 18
Let the numbers be 3x,5x and 6x. (3x)²+(5x)²+(6x)²=280 9x²+25x²+36x²=280 70x²=280 x²=4 x=2 The greatest number is 6x=12.

A. 9:19
B. 19:9
C. 15:28
D. 28:15
Let A1 be the area of flat and A2 be that of the commercial space
Total cost = area * rate
Therefore, cost of flat = A1*4500 ; cost of commercial space = A2*9500
Both the above costs are same
A1*4500 = A2*9500
A1:A2 = 9500:4500 = 19:9

A. 44
B. 55
C. 66
D. 77
Let the numbers be a, b and c. a+b+c = 172 a:b = 8:11 b:c = 5:7 11a = 8b a = 8b/11 7b = 5c c = 7b/5 (8b/11)+b+(7b/5) = 172 40b+55b+77b = 172*55 172b = 172*55 b=55

A. Rs.18000
B. Rs.13000
C. Rs.15000
D. Rs.10000
4S+5D+3C=130000 3C=2D 3D=2S S=3D/2 [4*(3D/2)]+5D+2D = 130000 6D+5D+2D = 130000 13D = 130000 D = Rs.10000 S=3D/2 = Rs.15000

A. 4
B. 6
C. 3
D. 2
Let the numbers be 2x and 3x. (2x)³+(3x)³=280 8x³+27x³=280 35x³=280 x³=8 x=2 The numbers are 4 and 6.

A. 38
B. 35
C. 10
D. 28
Let z = 4y-1
When x = 14, y = 2, z = (4*2) – 1 = 7
Now, x varies directly as z = 4y-1
When y = 5, z = (4*5) – 1 = 19
x 14 7
y – 19
Therefore, x = (14*19)/7 = 38