The event that either M1 or M2 fails has probability

by the addition rule. Failure events are independent, so

so that

Denote this probability by
. Then
follows a geometric distribution with this parameter
and has density

The expectation is
.
Step-by-step explanation:
Given the expression:

Follow BODMAS rule.
always evaluate brackets first, followed by multiply or division then addition or subtraction from LEFT to RIGHT.

Its one of the two first ones, I can’t really figure it out but that’s a hint
Answer:
68
Step-by-step explanation:
Find the vanilla first by dividing 420 by 7 and multiplying the quotient by 2 to get 120.
Then find the banana using the equation 35/100 = x/420, cross multiply to get 147.
Add 120 and 147 to get 267.
Subtract 267 from 420 to get 153.
Divide 153 by 9 to get 17.
Get the number of lemon cakes by multiplying 17 by 4.
The number of lemon cakes is 68!
(and chocolate cakes is 85)
Problems are very often written in a confusing way. This one couldn't possibly have been
written any more clearly. Sooner or later, you have to stop telling yourself that you have
no clue, settle down, and carefully read the words that are right there on the page.
I'll tell you one more detail that's not in the problem: "breadth" means "width".
Now. The problem clearly tells you all of these things, in this exact order:
=> Area of the walls = (2 x height) x (length + width)
=> length = 8m
=> width = 6m
=> height = 2.5m
Is there a reason you can't take the numbers for length, width, and height,
and write them in the formula for the area ? Do I have to do all the work ?
Area = (2 x height) x (length + width)
Area = (2 x 2.5m ) x ( 8m + 6m )
Do the arithmetic inside the parentheses:
Area = ( 5m ) x ( 14m )
Do the multiplication:
Area = <u>70 m² .</u>
You will never see a problem that comes any closer to answering itself <em>for </em>you.