Answer:
£110
Step-by-step explanation:
We know how much time it takes for a boiler and a radiator, and we need to know how much it will cost for 1 boiler and 4 radiators. We have an initial cost of £30, and since hes doing a boiler - which we know takes an hour - we can already add £20 for a start of £50.
Now, there are 4 radiators, that take 45 minutes each. We need to use this equation:

We divide by 60 because there are 60 minutes in an hour, and he charges by hour. So:

Now, to find out how much to charge, we need to figure out how much to add to the £50. Since it's £20 an hour, and it takes 3 hours to do the 4 radiators, we need to multiply:

Now we add our totals for a grand total of...

Answer:
Step-by-step explanation:
2. area of a triangle is 1/2 b h
1/2 (5 * 2) = 5 yd squared
area of the circle is pi r squared
you only need 1/2 of this area
find all these areas and add them together.
6. this is just a square sitting on a rectangle.
36 x 36 for the square
36 x 60 for the rectangle
add these together.
8. this a 1/2 circle and a triangle.
area of a circle is pi r squared
r is 7 in this problem
the area of a triangle is 1/2 b h
height is 7x2 here or 14
add the two together.
Answer:
The speed of the boat is 20 km/hr
Step-by-step explanation:
Let s be the speed of boat in still water
Let d be the distance
Upstream speed = s-4
Jane took 30 min to drive her boat upstream to water-ski at her favorite spot.
So, Distance traveled in upstream =
Downstream speed = s+4
So, Distance traveled in downstream = 
So, 
30s-120=20s+80
10s=200
s=20
Hence The speed of the boat is 20 km/hr
Hope this answer is helpful for you
Answer:
8
Step-by-step explanation: