7 = -x + 3
7- 3 = -x
4 = -x
x = -4 <===== 10 is not a solution
If the recipe needs 200g of chocolate bars, and that recipe feeds 8 people, you need to figure out how many times you'd have to make a recipe to feed 50 people.
50 is not a factor of 8, so we have to break the recipe down. if 200g of chocolate feeds 8 people, then it's safe to assume that 100g feeds 4 people, and 50g feeds 2 people.
The closest you get to 50 without exceeding it by a factor of 8 is 6 x 8= 48. You'd be missing the chocolate for two people, all you have to do is add 50 grams of a chocolate bar.
You have to multiply each ingredient by 6 therefore everything is exactly the same, just amplified. 200 x 6 =1200, which means you'd need 1200g of chocolate bars + 50g to make a mousse for 50 people.
Each chocolate bar has 150g, so now what you do is you get the 1250g and divide it by 150g. This will tell you the amount of chocolate bars you need to complete the recipe for 50 people. The answer is 8.33333, which means Tim will have to buy 9 chocolate bars.
Given:
The tens digit of a two digit number is 5 greater the units digit.
If you subtract double the reversed number from it, the result is a fourth of the original number.
To find:
The original number.
Solution:
Let n be the two digit number and x be the unit digit. Then tens digit is (x+5) and the original number is:
Reversed number is:
If you subtract double the reversed number from it, the result is a fourth of the original number.
Multiply both sides by 4.
Divide both sides by 55.
The unit digit is 2. So, the tens digit is 
.
Therefore, the original number is 72.
