![lizzy2951](/avatars/18307.jpg)
lizzy2951
29.08.2021 •
Mathematics
60% of the cost price and 40% of the selling price are equal. find the profit or loss percentage
Solved
Show answers
More tips
- C Computers and Internet How to Set Up Internet on iPhone? Detailed Guide with Step-by-Step Instructions...
- F Family and Home How to Teach Your Child to Speak: Tips and Recommendations...
- P Philosophy Agnosticism: Opinion or Belief?...
- S Style and Beauty How to choose the best mascara for your eyelashes...
- F Food and Cooking Discover Delicious Recipes You Can Make with Ground Meat...
- C Computers and Internet Google Search Tips and Tricks: Everything You Need to Know...
- S Science and Technology Why is there no gravity on other planets?...
- L Leisure and Entertainment How to Properly Wind Fishing Line onto a Reel?...
- L Leisure and Entertainment How to Make a Paper Boat in Simple Steps...
- T Travel and tourism Maldives Adventures: What is the Best Season to Visit the Luxurious Beaches?...
Answers on questions: Mathematics
- M Mathematics Can anyone help me with the geometry translations...
- B Biology Would the carrying capacity of an area for a species be affected by the other species that live in the same area? A Only if the species in question and the second...
- G Geography How does erosion by runoff differ from stream erosion?...
- B Biology Which of the following is not found in cartilage but is found in bone? a) living cells b) lacunae c) blood vessels d) organic fibers...
Ответ:
answer:
1702.5
step-by-step explanation:
the n th term of an arithmetic progression is
= a + (n - 1)d
where a is the first term and d the common difference, hence
a + 5d = - 5 → (1) and
a + 9d = 21 → (2)
subtract (1) from (2) term by term
4d = 26 ( divide both sides by 4 )
d = = 6.5 ← common difference
substitute d = 6.5 into (1 )
a + 32.5 = - 5 ( subtract 32.5 from both sides )
a = - 37.5 ← first term
the sum to n terms of an arithmetic progression is
= [ 2a + (n - 1)d ], hence
= 15 [ - 75 + (29 × 6.5) ]
= 15 [ - 75 + 188.5 ]
= 15 × 113.5
= 1702.5