Hmmmmmm ok i know how to do this
We are given the expression:
U = E * P
The equality symbol “ = “ means that for all cases, the
value of U and E * P must always be equal. This means that whatever happens on
the left side, must equally happen on the right side.
So what this actually means is that, if we double U so we
must also double the expression E * P, that is:
2 U = 2 (E * P)
However since P stays constant in the process, therefore
only E is changed, hence:
2 U = P * 2 E
So we can see that E is also doubled.
There are two ways you can do this. You can use the longer way:
15+16+17+18+19+20+21+22+23+24 = 195 (starting from the top row, which has 15 logs, up until the bottom row, which has 24 logs, on condition that each second row has one log more than the previous one)
You can also use the formula (where n is the number of rows)
x= (n(first term+last term))/2
x= (10(15+24))/2
x= (10*39)/2
x=390/2
x=195
Either way, there are 195 logs in the stack.
