11. 

A rectangular field is to be fenced on three sides leaving a side of 20 feet uncovered. If the area of the field is 680 sq. feet, how many feet of fencing will be required?

A. 34
B. 40
C. 68
D. 88

12. 

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 m2
B. 2420 मीटर 2
C. 2480 मीटर >2
D. 2520 मीटर 2

13. 

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

A. 25% increase
B. 50% वृद्धि
C. 50% कमी
D. 75% कमी

14. 

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. 50
C. 120
D. अपर्याप्त डेटा

15. 

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. 458 रुपये
C. 558 रुपये
D. 568 रुपये