The ratio of the volumes of two cubes is 729 : 1331. What is the ratio of their total surface areas?
A. 81 : 121
B. 9 : 11
C. 729 : 1331
D. 27 : 12
Ratio of the sides = ³√729 : ³√1331 = 9 : 11
Ratio of surface areas = 92 : 112 = 81 : 121
A. 81 : 121
B. 9 : 11
C. 729 : 1331
D. 27 : 12
Ratio of the sides = ³√729 : ³√1331 = 9 : 11
Ratio of surface areas = 92 : 112 = 81 : 121
A. 130
B. 135
C. 142
D. 148
Explanation:
109 * 34 – 108 * 33
= 3706 – 3564 = 142
A. 5m
B. 12m
C. 13m
D. 14.5m
A. 9 %
B. 30 %
C. 60 %
D. 69 %
Explanation:
Let, side = 100cm.
Area = (100 × 100) cm2 = 10000 cm2
New area = (130 × 130) cm2 = 16900 cm2
Increase in area = (6900/10000 ×100) % = 69 %
A. Rs. 25000
B. Rs. 20000
C. Rs. 15000
D. Rs. 22000
E. None of these
Explanation:
Let the total worth of the stock be Rs. x.
The SP of 20% of the stock = 1/5 * x * 1.1 = 11x/50
The SP of 80% of the stock = 4/5 * x * 0.95 = 19x/25 = 38x/50
Total SP = 11x/50 + 38x/50 = 49x/50
Overall loss = x – 49x/50 = x/50
x/50 = 400 => x = 20000
A. 24.3 m
B. 243 m
C. 2430 m
D. 24300 m
A. 3/22
B. 4/21
C. 2/21
D. 1/14
Explanation:
Given that there are three blue marbles, four red marbles, six green marbles and two yellow marbles. Probability that both marbles are blue = ³C₂/¹⁵C₂ = (3 * 2)/(15 * 14) = 1/35
Probability that both are yellow = ²C₂/¹⁵C₂ = (2 * 1)/(15 * 14) = 1/105
Probability that one blue and other is yellow = (³C₁ * ²C₁)/¹⁵C₂ = (2 * 3 * 2)/(15 * 14) = 2/35
Required probability = 1/35 + 1/105 + 2/35
= 3/35 + 1/105 = 1/35(3 + 1/3)
= 10/(3 * 35) = 2/21