2hr = 2km
1hr = 2km ÷ 2hr
= 1km
So, Tom's average speed is 1km/hr
D economic growth was threatened
this can be solved by establishing system of
eqution:
let x be the amount of 25 % acid soln needs to
be drained
y is the amount of 70% acid solution
first equation:
<span>(100 – x) + y
= 100</span>
Second equation
0.25(100 – x ) + 0.7y = 0.60(100)
Solving the system of equation
<span>X = 77.78 g of 25 % acid solution is needed to
be drained</span>
They all should be 60* because it’s an acute angle
