The volumes of two cubes are in the ratio 27: 125, what shall be the ratio of their surface areas?
A. 6:25
B. 3:5
C. 9:25
D. 16:25
a13 : a23 = 27 : 125
a1 : a2 = 3 : 5
6 a12 : 6 a22
a12 : a22 = 9 : 25
A. 6:25
B. 3:5
C. 9:25
D. 16:25
a13 : a23 = 27 : 125
a1 : a2 = 3 : 5
6 a12 : 6 a22
a12 : a22 = 9 : 25
A. 80%
B. 20%
C. 40%
D. 50%
E. None of these
Explanation:
Number of students passed = 60% of 140 = 60/100 * 140 = 84
Number of students failed = 140 – 84 = 56.
Required percentage = 28/56 * 100 = 50%.
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. 1
B. 2
C. 3
D. 5
Explanation:
8/15 * 3/4 * 3 ?/4 = 1.5
=> 3 ?/4 = 3/2 * 5/2 = 15/4 = 3 3/4
=> ? = 3.
A. 3.34
B. 2
C. 4.5
D. 5.5
Area of the path = Area of the outer circle – Area of the inner circle = ∏{4/2 + 25/100}2 – ∏[4/2]2
= ∏[2.252 – 22] = ∏(0.25)(4.25) { (a2 – b2 = (a – b)(a + b) }
= (3.14)(1/4)(17/4) = 53.38/16 = 3.34 sq m
A. 12
B. 11
C. 10
D. 9
speed of the bus excluding stoppages = 54 kmph
speed of the bus including stoppages = 45 kmph
Loss in speed when including stoppages = 54 – 45 = 9kmph
=> In 1 hour, bus covers 9 km less due to stoppages
Hence, time that the bus stop per hour = time taken to cover 9 km
=distance/speed=9/54 hour=1/6 hour = 60/6 min=10 min
A. 2 years
B. 3 years
C. 1 year
D. 4 years
P = Rs.900
SI = Rs.81
T = ?
R = 4.5%
T=100×SI/PR =100*81/900*4.5 =2 years