To find speed, you use this equation:
distance÷time=speed
Let's do that with each.
3÷1=3
High Tide= 3 km/h
5÷2=2.5
Monsoon= 2.5 km/h
14÷4=3.5
Tsunami=3.5 km/h
N=8+d
10d+5n=145
divide 2nd equaiton by 5 to make nicer and easier
2d+n=29
subsitute 8+d for n in 2nd equation
2d+8+d=29
3d+8=29
minus 8 both sides
3d=21
divide by 3
d=7
sub back
n=8+d
n=8+7
n=15
15 nickles and 7 dimes
Answer:

Step-by-step explanation:

Step-by-step explanation:
estimate the sums and round the numbers to the neares hundred