A can do of a work in 5 days and B can do th of this work in 10 days. Both A and B, together can do the work in
10 days
The base area of a right pyramid is 57 sq units and height is 10 units. Then the volume of the pyramid is:
190 c. units
380 c. units
540 c. units
570 c. units
The marked price of a ceiling fan is â¹ 1,200/- and the shopkeeper allows a discount of 5% on it. Then selling price of the fan is
â¹ 1,410
â¹ 1,400
â¹ 1,140
â¹ 1,104
If 35% of A's income is equal to 25% of B's income, then the ratio of A's income to B's income is:
7 : 5
5 : 7
4 : 7
4 : 3
A and B invest â¹ 3,000/- and â¹ 2,400/- respectively in a business. If after one year there is a loss of â¹ 720/-, how much loss will B bear? (Loss or profit in proportion to their investments)
â¹ 72/-
â¹ 320/-
â¹ 400/-
â¹ 360/-
At an average of 80 km/hr Shatabdi Express reaches Ranchi from Kolkata in 7 hours. Then the distance between Kolkata and Ranchi is:
560 km
506 km
560 m
650 m
If a3 - b3 = 56 and a - b = 2, then what is the value of a2 + b2 ?
12
20
28
32
B.
20
(a - b)3 = a3 - b3 - 3ab(a - b)
(2)3 = 56 - 3ab(2)
8 = 56 - 6ab
6ab = 48
ab = 8
(a - b)2 = a2 + b2 - 2ab
(2)2 = a2 + b2 - 2 x 8
4 = a2 + b2 - 16
∴ a2 + b2 = 20
X and Y are the mid-points of sides of AB and AC of Δ ABC. If BC + XY = 12 units, then BC - XY is:
8 units
4 units
6 units
2 units