Speed, S = Distance (d) / Time (t) => S= d/t => t= d/S
Let the speed of boat in still water be x mph
Resulting speed upstream = x-4 mph for a distance of 30 miles
Resulting speed downstream = x-4 mph for a distance of 50 miles
Time taken in both distances is equal.
Therefore,
30/(x-4) = 50/(x+4) => 30(x+4) = 50(x-4) => 30x+120 = 50x-200 => 120+200 = (50-30)x => 20x = 320 => x=320/20 = 16 mph
The speed of boat in still water is 16 mph.
1 Convert 12\frac{2}{3}12
3
2
to improper fraction. Use this rule: a \frac{b}{c}=\frac{ac+b}{c}a
c
b
=
c
ac+b
\frac{12\times 3+2}{3}\times 3\frac{1}{4}
3
12×3+2
×3
4
1
2 Simplify 12\times 312×3 to 3636
\frac{36+2}{3}\times 3\frac{1}{4}
3
36+2
×3
4
1
3 Simplify 36+236+2 to 3838
\frac{38}{3}\times 3\frac{1}{4}
3
38
×3
4
1
4 Convert 3\frac{1}{4}3
4
1
to improper fraction. Use this rule: a \frac{b}{c}=\frac{ac+b}{c}a
c
b
=
c
ac+b
\frac{38}{3}\times \frac{3\times 4+1}{4}
3
38
×
4
3×4+1
5 Simplify 3\times 43×4 to 1212
\frac{38}{3}\times \frac{12+1}{4}
3
38
×
4
12+1
6 Simplify 12+112+1 to 1313
\frac{38}{3}\times \frac{13}{4}
3
38
×
4
13
7 Use this rule: \frac{a}{b}\times \frac{c}{d}=\frac{ac}{bd}
b
a
×
d
c
=
bd
ac
\frac{38\times 13}{3\times 4}
3×4
38×13
8 Simplify 38\times 1338×13 to 494494
\frac{494}{3\times 4}
3×4
494
9 Simplify 3\times 43×4 to 1212
\frac{494}{12}
12
494
10 Simplify
\frac{247}{6}
6
247
11 Convert to mixed fraction
41\frac{1}{6}41
6
1
41 and 1/6
25% of $56 is $14.00.
(0.25)(56) = 14
Subtract $14.00 from $56 = $42.00.
56 - 14 = 42
The boots will cost $42 on sale.
Answer:
0.5
Step-by-step explanation:
hypotenuse/adjacent=r
7/14=0.5
