its Search

Q:

The slant height of a right circular cone is 10 m and its height is 8 m. Find the area of its curved surface

A) 40pi sq.m	B) 50pi sq.m
C) 60pi sq.m	D) 70pi sq.m

Answer & Explanation Answer: C) 60pi sq.m

Explanation:

Report Error

View Answer Report Error Discuss

Filed Under: Volume and Surface Area

Q:

A metallic sheet is of rectangular shape with dimensions 48 m x 36 m. From each of its corners, a square is cut off so as to make an open box. If the length of the square is 8m, the volume of the box (in m³) is:

A) 4830	B) 5120
C) 6420	D) 8960

Answer & Explanation Answer: B) 5120

Explanation:

Report Error

View Answer Report Error Discuss

Filed Under: Volume and Surface Area

Q:

A hollow iron pipe is 21 cm long and its external diameter is 8 cm. If the thickness of the pipe is 1 cm and iron weighs 8g/cu.cm, then the weight of the pipe is

A) 3.6 kg	B) 3.696 kg
C) 36 kg	D) 36.9 kg

Answer & Explanation Answer: B) 3.696 kg

Explanation:

External radius = 4 cm

Internal radius = 3 cm

Volume of iron = $[\frac{22}{7} \times (4^{2} - 3^{2}) \times 21] c m^{3}$ = $462 c m^{3}$

Weight of iron = (462 x 8)gm = 3696 gm = 3.696 kg

Report Error

View Answer Report Error Discuss

Filed Under: Volume and Surface Area

Q:

A tank is 25 m long, 12 m wide and 6 m deep. The cost of plastering its walls and bottom at 75 paise per sq. m, is:

A) Rs. 456	B) Rs. 458
C) Rs. 558	D) Rs. 568

Answer & Explanation Answer: C) Rs. 558

Explanation:

Area to be plastered= [2(l + b) x h] + (l x b)

= [2(25 + 12) x 6] + (25 x 12)

= (444 + 300)

= 744

Cost of plastering = Rs. 744 x (75/100)= Rs. 558

Report Error

View Answer Report Error Discuss

Filed Under: Volume and Surface Area

Q:

The length of a rectangular plot is 20 metres more than its breadth. If the cost of fencing the plot @ 26.50 per metre is Rs. 5300, what is the length of the plot in metres?

A) 40	B) 120
C) 50	D) None of these

Answer & Explanation Answer: D) None of these

Explanation:

Let breadth = x metres.

Then, length = (x + 20) metres.

Perimeter = 5300 m = 200 m. 26.50

2[(x + 20) + x] = 200

2x + 20 = 100

2x = 80

x = 40.

Hence, length = x + 20 = 60 m.

Report Error

View Answer Report Error Discuss

Filed Under: Volume and Surface Area

Q:

The length of a rectangle is halved, while its breadth is tripled. What is the percentage change in area?

A) 25% increase	B) 50% increase
C) 50% decrease	D) 75% decrease

Answer & Explanation Answer: B) 50% increase

Explanation:

Let original length = x and original breadth = y.

Original area = xy.

New length = x/2 and New breadth = 3y.

New area = (x/2 * 3y) = (3/2 )xy

Therefore, Increase % = [(1/2)xy * (1/xy) * 100] % = 50%

Report Error

View Answer Report Error Discuss

Filed Under: Volume and Surface Area

Q:

The difference between the length and breadth of a rectangle is 23 m. If its perimeter is 206 m, then its area is:

A) 1520 sq.m	B) 2420 sq.m
C) 2480 sq.m	D) 2520 sq.m

Answer & Explanation Answer: D) 2520 sq.m

Explanation:

We have: (l - b) = 23 and 2(l + b) = 206 or (l + b) = 103.

Solving the two equations, we get: l = 63 and b = 40.

Area = (l x b) = (63 x 40) sq.m

= 2520 sq.m

Report Error

View Answer Report Error Discuss

Filed Under: Volume and Surface Area

Q:

The diagonal of a rectangle is sqrt(41) cm. and its area is 20 sq. cm. The perimeter of the rectangle must be:

A) 9 cm	B) 18 cm
C) 20 cm	D) 41 cm

Answer & Explanation Answer: B) 18 cm

Explanation:

$l^{2} + b^{2}$ = ${(d i a g o n a l)}^{2}$ =40

Also, lb=20

${(l + b)}^{2} = l^{2} + b^{2} + 2 l b$ = 41 + 40 =81

(l + b) = 9.

Perimeter = 2(l + b) = 18 cm.

Report Error

View Answer Report Error Discuss

Filed Under: Volume and Surface Area

Searching for "its"

Quick Links