Answer:
The speed on motorboat is 20 mph
Step-by-step explanation:
here, we want to find the speed on the motorboat
if he has a speed of x mph on the motor boat, his speed on the ski will be (x + 10) mph
The total hours is 4 hours
Mathematically; speed = distance/time
Time on ski is 27/x+ 10
Time on motor boat is 62/x
The addition of both is 4
Thus;
27/(x + 10) + 62/x = 4
27(x) + 62(x + 10) = 4(x)(x + 10)
27x + 62x + 620 = 4(x^2 + 10x)
89x + 620 = 4x^2 + 40x
4x^2 -49x-620 = 0
using the quadratic formula;
{-b ± √(b^2-4ac)}/2a
where a = 4, b = -49 and c = -620
= 49 ± √(-49)^2-4(4)(-620)/8
So we have
49+ 111/8 or 49-111/8
Speed cannot be negative
(49 + 111)/8
= 20 mph
The answer should be 140, I hope this helps! Have a fantastic day!!
I would choose the answer D
The answer to this question would be: <span>The new survey’s margin of error will be between 50% and 100% the size of the original survey’s margin of error.
A bigger sample will result in a narrower margin of error which is a good thing because your data will become more accurate. But twice size will not improve the margin into the half. It definitely became lower than 100% though
</span>
Answer:
16
Step-by-step explanation:
1. Use a vertical number line to count how many spaces are between -6 and 10.
