85 x 3 = 255
first 2 test grades were 81 and 86:
81 + 86 = 167
Need to find the 3rd to have exact average 85:
255 - 167 = 88
So her 3rd test needs to make 88 to make average of 85
Double check: 81 + 86 + 88 = 255 = 85 + 85 + 85
Answer:
There is no variable factor common to 24a and 6
Step-by-step explanation:
First number = 24a
Other number = 6
Pime factorisation of 24a = 2×2×3×2×a
Pime factorisation of 6= 3×2
Common factors = 6
Hence, there is no variable factor common to 24a and 6, Other common factor is 6.
Answer: B. The product of P and S is always a rational number.
Step-by-step explanation: The product AND sum of two rational numbers will ALWAYS be rational.
If
than
however any
divided by 2 is in
.
But it is not so simple.
If
is odd then
is even but when even number is divided by 2, you get an odd number which is in
.
However if
is even then
is odd and when we divide that by 2, you get a number like for example
which is not in
but rather inside
. There are fortunately no irrational numbers.
There is also a problem with zero, zero is neither odd nor even but still an integer. If your
happens to be -1,
, and zero divided by 2 is still just 0 which is in
.
So to sum up,
If
is odd and not -1, then
.
Or to put it in math
.
If
is even or -1, then
.
Or to put it in math
.
<u>Notes</u>:
is a set of integers.
is a set of rational numbers.
means integers are a subset of rational numbers, that is, every integer is a also a fraction, however not every fraction is an integer.
Hope this helps :)