182.17+92.55+225.82+127.94= 628.48
the second digit, 2, is less than or equal to 4 so it rounds down to 0.
Answer: $600
Answer:
4 packages of AA batteries
6 packages of AAA batteries.
Step-by-step explanation:
Let the number of packages of AA batteries bought be x
Let
the number of packages of AAA batteries bought be Y
He Brought 10 packages of AA and AAA
thus,
x+y = 10 equation 1
Given
The AA batteries are sold in packages of 6, it means one packet contains 6 batteries
Thus,
Total number of AA batteries in x packages = 6x
The AAA batteries are sold in packages of 8, it means one packet contains 8 batteries
Thus,
Total number of AAA batteries in y packages = 8y
Given total no. of batteries is 72
thus
6x + 8y = 72 equation 2
x+y = 10
y = 10-x ---using this in equation 2
6x + 8(10 - x) = 72
=> 6x + 80 - 8x = 72
=> -2x = 72-80 = -8
=> x = -8/-2 = 4
y = 10 -x = 10 -4 = 6
y = 6
Thus,
he bought 4 packages of AA batteries
6 packages of AAA batteries.
When they work together, it takes John 1/x hours and it takes Brian 1/(x+15) hours to complete 1/4 of the model.
1/x + 1/( x+15 ) = 1/4 / · x ( x+15 )
x+15 + x = x ( x+15 ) /4 / · 4
8 x + 60 = x² + 15 x
x² + 15 x - 8 x - 60 = 0
x² + 7 x - 60 = 0
x² + 12 x - 5 x - 60 = 0
x · ( x + 12 ) - 5 ·( x+ 12 ) = 0
( x + 12 ) · ( x - 5 ) =0
x = - 12 ( not accepted ) or x = 5
The time taken by Brian: 5 + 15 = 20 hours