Answer:
40 min
Step-by-step explanation:
his sister can do it twice as fast so the boy does 1 and the sister does 2. he will do 1/3 of the work and it will take 1/3 of the time
Answer:
es la respuesta de amigo mío es la d la respuesta
800 + 16x = 720 + 21x. Cancel out the 720 to get 80 + 16x = 21x. Subtract 16x from both sides to get 80 = 5x. Divide by 5 to get 16 = x, or x = 16. 16 hours. The charge is 800 + 16(16), = 720 + 21(16) which = 800 + 256 = 720 + 336 which = 1,056 = 1,056. Hope this helped!
Let A and B be the two complementary angles.
A = smaller angle = 2x
B = larger angle = 13x
x = some unknown number
Note how the ratio A:B turns into 2x:13x which simplifies to 2:13
A+B = 90 ... because the angles are complementary
2x+13x = 90 ... substitution
15x = 90
x = 90/15
x = 6
A = 2*x = 2*6 = 12 degrees
B = 13*x = 13*6 = 78 degrees
The two angles are 12 degrees and 78 degrees.
Check:
A/B = 12/78 = (2*6)/(13*6) = 2/13, so A:B = 2:13
A+B = 12+78 = 90
