Answer:
?
Step-by-step explanation:
The answer is A. he can make 1 in 2 hours
The balloon has a volume
dependent on its radius
:

Differentiating with respect to time
gives

If the volume is increasing at a rate of 10 cubic m/s, then at the moment the radius is 3 m, it is increasing at a rate of

The surface area of the balloon is

and differentiating gives

so that at the moment the radius is 3 m, its area is increasing at a rate of

Answer:
300 i think hope it helps
Answer:
the answer for this question is 15/14
to find area the formula is area = l×b
here length is 1 1/4 and breadth is 3/4 so l×b = 1 1/4=5/4 so 5/4×3/4=15/14