Let be the 20 marks of the boys, and be the 10 marks of the girls.
We know that the global mean was 70, meaning that
Multiplying both sides by 30 we deduce that the sum of the scores of the whole classroom is
By the same logic, we work with the marks of the boys alone: we know the average:
And we deduce the sum of the marks for the boys:
Which implies that the sum of the marks of the girls is
And finally, the mean for the girls alone is
Answer:
-25.5
8x3=24
but we still have the .5 so we multiply that by 3 which equals to 1.5 add that to 24 which makes 25.5 and because only one of the numbers was negative it turns 25.5 into -25.5.
So 5
then 5 times 5
then 5 times 5 times 5
so it seems that for x rounds, there will be 5^x
A: 4 rounds so 5^4=625 photos
B. see how many times 5 goes into 78125. the answer is 7 so 7 rounds
C. 1 million=1,000,000 so try big numbers
5^10=9,765,625 too big
5^9=1,9,53,125 too big
5^8=390625 too small
the minimum is 5^9 or 9 rounds
A:4
B:7
C:9
Answer:
x=1
Step-by-step explanation:
Divide both sides by the numeric factor on the left side then solve.
Hope this helps.