Ratio of per meter fencing cost to the per square meter gardening cost is 15 : 4 and ratio of total cost of fencing to the total cost of gardening a circular field is 5 : 7, then what is the circumference of the circular field?
Ratio of per meter fencing cost to the per square meter gardening cost is 15 : 4 and ratio of total cost of fencing to the total cost of gardening a circular field is 5 : 7, then what is the circumference of the circular field? Correct Answer 66 meters
Given:
Ratio of per meter fencing cost to the per square meter gardening cost is 15 : 4
Ratio of total cost of fencing to the total cost of gardening a circular field is 5 : 7
Formula used:
Circumference of circle = 2 π r
Calculation:
Let radius of the circular field be r
Let per meter fencing cost and per square meter gardening cost be 15x and 4x respectively.
Total cost of fencing the field = 15x × 2πr = 15x × 2 × (22/7) × r = 660xr/7
Total cost of gardening the field = 4x × πr2 = 4x × (22/7) × r2 = 88xr2/7
According to the question:
(660xr/7) : (88xr2/7) = 5 : 7
r = 21/2
r = 10.5 cm
Circumference of the circular field = 2πr = 2 × (22/7) × 10.5 = 66 meters