Answer: 12 friends.
Step-by-step explanation:
the data we have is:
Mei Su had 80 coins.
She gave the coins to her friends, in such a way that every friend got a different number of coins, then we have that:
The maximum number of friends that could have coins is when:
friend 1 got 1 coin
friend 2 got 2 coins
friend 3 got 3 coins
friend N got N coins
in such a way that:
(1 + 2 + 3 + ... + N) ≥ 79
I use 79 because "she gave most of the coins", not all.
We want to find the maximum possible N.
Then let's calculate:
1 + 2 + 3 + 4 + 5 = 15
15 + 6 + 7 + 8 + 9 + 10 = 55
now we are close, lets add by one number:
55 + 11 = 66
66 + 12 = 78
now, we can not add more because we will have a number larger than 80.
Then we have N = 12
This means that the maximum number of friends is 12.
Step-by-step explanation:
90.......................
The domain is the set of all x values which are defined (appear on the graph) of the function. In this system, all values from negative infinity to 0, but not including zero, and all values above zero, through positive infinity, are valid. We can write this in set builder notation as x: (-∞,0)∪(0,∞).
The range is the set of all y values which are defined in the function. Like the domain, the range of this function contains all value from negative infinity to positive infinity except zero. Same notation: y: : (-∞,0)∪(0,∞).
