Answer:the price for one shirt is $7.5
the price for one pair of pants is $18.5
Step-by-step explanation:
Let x represent the price for one shirt.
Let y represent the price for one pair of pants.
Lisa goes to the mall one day and buys four shirts and three pairs of pants for $85.50. This means that
4x + 3y = 85.5 - - - - - - - - - -1
She returns the next day and buys three shirts and five pairs of pants for $115.00. This means that
3x + 5y = 115 - - - - - - - - - - - 2
Multiplying equation 1 by b3 and equation 2 by 4, it becomes
12x + 9y = 256.5
12x + 20y = 460
Subtracting, it becomes
- 11y = - 203.5
y = - 203.5/ -11 = 18.5
Substituting y = 18.5 into equation 1, it becomes
4x + 3×18.5 = 85.5
4x + 55.5 = 85.5
4x = 85.5 - 55.5 = 30
x = 30/4 = 7.5
I’m pretty sure it’s the first one! Goodluck :)
Answer:
the correct answer is use a calculator
Step-by-step explanation:
Answer:
Step-by-step explanation:
Given that x is a random variable from a binomial distribution with n = 40 and p = 0.9.
We find that mean = np= 36 and variance = npq = 3.6
Std dev = square root of variance = 1.897
When we approximate binomial to normal we say
X' is Normal with mean = 36 and std dev = 1.897
X' is N(36, 1.897)
Note:
The condition for binomial approximating to normal is p should be close to 1/2
Here p is 0.9 and also nq=4 is very small.
So normal approximation may not give accurate results.
S = total # of students / #of students in each group
So you can do, s= t/g
Overall, the answer is 4 students per group
