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
Average speed is the distance traveled by an object in total and divided by the amount of time an object covers the distance. The formula is -
Average speed = total distance traveled / total time taken
= 68km+64km / 2 hrs.+3hrs.
= 132km / 5hrs.
= 26.4km/hr.
Therefore, the train's average speed is 26.4km/hr.
Answer:
unlikely
Step-by-step explanation:
thats alot of people
Okay! Assuming this only wants the tax that will be added to the total, multiply the decimal percent by the cost of the item.
7.5% = .075
14.80 * .075 = 1.11
1.11 of tax will be added onto the total cost.
The total cost would be 15.91, which you can get from adding 14.80 to 1.11 or by doing 14.80 * 1.075. Regardless, the answer to this question is 1.11.
