In order to get the common denominator when adding fractions or subtracting fractions, you have to make sure that the denominator of the two items are divisible by each other. In this case, 9 is not divisible by any of the given denominators which is 4 and 5. So in this case, the common denominator will have to be 20. 5 x 4 will equal to 20 and you will also multiply 3 x 5 to get the new numerator. After that, you will multiply 2 x 4 to get the new numerator of the other fraction. The new fractions will be 15/20 and 8/20. From there, you can add or subtract
Since 120 students gained less than 70, and 70 is the upper quartile, 120 people are in the 75% of all the students so we need to find the total number of students.
we need to multiply 0.75 (75%) by something to get 120. which is 160 (the total number of all students).
and since 48 is the median score, find 50% of 160 which is 80!
hope this helps :)
Answer:
7
Step-by-step explanation:
Do addition first, so 30 plus 2, and then subtract, 32 minus 25. It is seven.