Answer:
D.
Step-by-step explanation:
It's a right triangle so

x = 41
Step-by-step explanation:
☄ 
- Length of a park ( l ) = 55 m
- Breadth of a park ( b ) = 35 m
- Width running outside the park ( d ) = 2.5 m
- Rate of paving the path with stones = Rs 120 per sq.metre
☄ 
- Area of the park
- Cosy of paving the path with stones at Rs 130 per sq.metre
☄ 
Part 1 : 
plug the known values and simplify :
⟹ 
⟹ 
⟹ 
Part 2 : 
⟹ 
⟹

Hope I helped ! ♡
Have a wonderful day /night ツ
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Remember that the general decay equation is:

where

is the amount after a time


is the initial amount

is the the decay percent in decimal form
The first ting we are going to do is find

by dividing our <span>decay rate of 25% by 100%: </span>

.
We also know from our problem that

. Lets replace

and

in our formula:


We know now that our decay rate is 0.75, and since 0.75<1, we can conclude that
this situation represents exponential decay.
Now, to find the initial amount, we are going to solve our equation for

:


Notice that

will depend on the number of ours

. <span />
B(cone)=B(pyramid)=r²π
V(pyramid)=1/3 * B * H = 1/3 * r² π * 3 r ( 3 will cancel out )= r³ π
Answer: r³ π