The answer is 20 stamps.
You can solve this by forming an equation with.
We know that she has a total of 50 at the end. So we will put the 50 stamps at the end of the equation and derive for the unknown.
She first gave 10 to her friend. This means we subtract first 10 from the unknown. Let x represent the unknown.
x-10
Afterwards Jane's mom bought her twice as many as she had at the beginning. So we know that we add twice as much as the unknown.
x-10+2x = 50
Now we solve. Let's arrange our terms by combining like terms:
3x - 10 = 50
Now we transpose the 10 to the other side of the equation:
3x = 50 + 10
3x = 60
And finally we transpose the 3 by the x to isolate x:
x = 60/3
= 20
She had 20 stamps in the beginning.
Answer:
Step-by-step explanation:
Hard to figure out huh
Answer:
A) 0.386
B).0.325
Step-by-step explanation:
probability p will not work = 0.15
Q probability w5ill work = 0.85
Number of flashlight = 3
Probabilty of at least one=
1- probability of none
But probability of none= 3C0(p)^0(q)^3
= 1*(0.15)^0(0.85)^3
= 1*1*(0.614)
= 0.614
Probability of at least one=1-0.614
= 0.386
Probability of two flashlight work
= 3C1(0.15)^1(0.85)^2
= 3*(0.15)*(0.7225)
= 0.325
