Answer:
A. 6
Step-by-step explanation:
Since, cake is of right triangled shape, so measure of its one angle would be 90° and the sum of the measures of the remaining two angles will also be equal 90°.
Therefore,
5x +10x = 90
15x = 90
x = 90/15
x = 6
(6•2 - 3 - 5•3) - (4•3 + 2•2 - 8)
(12 - 3 - 15) - (12 + 4 - 8)
(9 - 15) - (16 - 8)
(-6) - (8)
-14
Let the speed of the boat be x
so going against the current the speed is x-7
going with the current the speed is x+7
let the distance be d
time = distance / speed
time to go against the current = d/(x-7)
time to go with the current = d/(x+7)
time going against the current is 3 times going <span>with the current
</span>
d/(x-7) = 3d/(x+7)
⇒⇒⇒ divide by d
1/(x-7)
= 3/(x+7)
x+7
= 3(x-7)
x+7 = 3x - 21
2x = 28
x = 14
So, the speed of the boat in still water is = 14 mph
