We XXXXX XXXX XXX XXXXX equation”. We’ll call this XXXXXXXX (i) for XXXXXXXXX purposes.
XXXXX of boat alone = 40 mph
XXX speed of current= c
XXX XXXX= t
When XXXX travels XXXX the
current, XXX speed XX the current XXXXXX boat along XXXXXXXXX,
Total XXXXX of XXXX= XXXXX XX boat XXXXX + XXXXX of XXXXXXX= ( 40+c )
XXXXXXX XXXX speed in XXXXXXXX (i),
(40+c) × t = 126
Multiplying out the XXXXXXXX
XXX + ct= XXX (XX’ll call this equation XX)
XXXX boat travels XXXXXXX the current, the speed of XXX XXXXXXX XXXXX boat back therefore,
Total XXXXX XX boat= XXXXX XX boat XXXXX speed XX XXXXXXX= (40c)
Again, XXXXXXX XXXX speed in equation (i),
(XXc ) × t = 126
XXXXXXXXXXX out the XXXXXXXX
XXX (XX’ll call this equation XXX)
XXXXXXXXX XXXXXXXXX ii and iii
XXX + XX= 126
XXX
Solving XXXXX as simultaneous equations, XX XXX XXX XXX XX the term ‘XX’ by adding both equations ii and XXX. XXXX gives:
40t + XX= XXX
+ XXX
80t = XXX
t=
t=3 XXXXX
Substitute or XXX ‘t=3 hours’ in XXXXXXXX ii
(40+c)
120+ 3c= XXX
3c= XXX-120
3c= 6
X=
X=2 XXX
Speed XX current= XXXX
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