Answer: -46
Step-by-step explanation: First you would do 2 x 2 because of Pemdas and the answer to that is 4 and when you subtract 4 from 50 you get -46
X - speed of the current
40+x - speed with current
40-x - speed against current
t-time
(40+x)*t=100
(40-x)*t=60
40t+xt=100
<span> + 40t-xt = 60
</span> 80t =160
t = 2
40t+xt=100,
40*2+2x=100
80+2x=100
2x=100-80
2x=20
x=10 mi/h
10 mi/h speed of the current.
60 ÷ h = y (or:how much he earned in one hour)
Answer: option A and option D
