A physics test has twenty questions worth 100 points. The test consists of true /false questions worth 3 points each and multiple choice questions worth 11 points each. How many multiple choice questions are on the test ?
number of T/F questions --- x
number of multiple choice --- 20-x
3x + 11(20-x) = 100
3x + 220 - 11x = 100
-8x = -120
x = 15
15 T/F questions and 5 multiple choices
If Mr.Chiko earns N$ x in a week and spend N$ y, what part of his weekly salary did he save?
To determine the number of multiple-choice questions on the test, we need to gather all the necessary information and use it to solve the problem.
Given information:
- The test has 20 questions in total.
- True/false questions are worth 3 points each.
- Multiple-choice questions are worth 11 points each.
- The total number of points for the test is 100.
Let's denote the number of multiple-choice questions as "x".
We can set up two equations based on the given information as follows:
1. The total number of questions:
True/false questions + Multiple-choice questions = Total questions
20 = x + y (where y represents the number of true/false questions)
2. The total number of points:
True/false points + Multiple-choice points = Total points
3y + 11x = 100
Now we have a system of two equations with two unknowns (x and y). We can solve this system to find the value of x (the number of multiple-choice questions on the test).
First, let's isolate y in the first equation:
y = 20 - x
Substitute this value of y into the second equation:
3(20 - x) + 11x = 100
60 - 3x + 11x = 100
8x = 40
x = 40/8
x = 5
Therefore, there are 5 multiple-choice questions on the test.