Answer:
The number of friends that went out for dinner is 8
And their bill is $238
Step-by-step explanation:
Let's assume that the number of friends that went out for dinner to be x
And the bill for the dinner to be y
If each person contributed $32 and paid off the bill,they will have a balance of $18
32x - 18 = y_____equation 1
If each person contributed $35 and paid off the bill and also 15% tip,they will have a balance of $6.30
35x - 6.3 = y + (15% of y)
35x - 6.3 = y + (3y/20)
Open up the bracket
35x - 6.3 =(20y + 3y)/20
700x - 126 = 23y______equation 2
From equation 1,y = 32x - 18
Put the above in equation 2 and we have
700x - 126 = 23(32x -18)
700x - 126 = 736x - 414
collect like terms
36x = 288
x = 288/36
x = 8
Remember that equation 1 says that y = 32x - 18 and we now know that x = 8 .
Substitute and we have
(32 × 8) - 18
y = 238
The number of friends that went out for dinner is 8
And their bill is $238
6.32 is the final answer! :)
It depends on what you are trying to calculate but the most common way I go to find percentage is to multiply by the number in decimal for ie. 50% = .5.
If you are looking for a way to do it quickly in your head I always take find out what 10% is like in the case of 100 it would be 10 so if I want to find 15% I know I can find 10% and if I cut what 10% is in half I will find 5% so likewise if I add what 10%+5% I will end up with 15%. For example, 10% of 100 is 10 half of 10 is 5 and 10+5 equals 15. If you need to find something like 20% or 30% I know that I can find 10% and instead of dividing(cutting it in half) I can multiply by 2 or 3. 10% + 10% =20%
I hope it helps, if you have more questions let me know!
Answer:
-0.4 or 2.3
Step-by-step explanation:
simple
each box is 0.1 unit
