Answer:
c
Step-by-step explanation:
Answer:
The second choice is the same so it is the last one
N + d = 21
0.5n + 0.10d = 1.35
5n + 10d = 135
d = 21-n
5n + 210 - 10n = 135
-5n = -75
n = 15
d = 6
<span>all real numbers less than or equal to 7</span>
Answer:
3 hours
Step-by-step explanation:
speed of Bharat = 12kilometers / hour
speed of Ingrid=14 kilometers / hour
For this problem we'll be using formula relating time, distance and speed.i.e
Distance = speed x time
Suppose Bharat is riding at a distance of 'b' kilometers, therefore time taken by him will be:
Time = distance/ speed
Time= b/12 hours.
Also, Ingrid can ride the distance at this time with speed of 14km/hr
The distance would be,
Distance = speed x time
Distance = 14 x (b/12) => 14b/12
Distance= 7b/6
Let '
' be the distance that Bharat have covered after time 't'
therefore,
= 12 x t
Let '
' be the distance that Ingrid have covered after time 't'
therefore,
= 14 x t
In order to find the time when they are 78 kilometers apart, we will add
and
, because they are travelling in opposite direction creating distance between them.
So,
+
= 78
( 14 x t) + (12 x t) =78
14t + 12t =78
26t= 78
t= 78/26
t= 3hours.
thus, it will take 3 hours until they are 78 kilometers apart