QUESTION:- A boat goes 30km in upstream and 44 km in downstream in 10hrs. In 13hrs ,it can go 40km upstream and 55 km downstream. Determine the speed of the stream and that of the boat in still water respectively

Time taken to cover 44 km downstream⇒x+y44

According to the first condition,

⇒x−y30=x+y44=10

Time taken to cover 40 km upstream ⇒x−y40

Time taken to cover 55 km downstream ⇒x+y55

According to the second condition,

⇒x−y40=x+y55=13

Let x−y1=uandx+y1=v

⇒30u+44v=10.....eq1⇒40u+55v=13.....eq2

Multiplying   eq1   by   3  and  eq2  by  5  and  subtract  both

⇒(150u+220v=50)−(160u+220v=52)

⇒−10u=−2⇒u=51

put  u=51 in eq1

⇒30×51+44v=10⇒44v=4⇒v=41

⇒u=x−y1=51⇒x−y=5...eq3

⇒v=x+y1=111⇒x+y=11...eq4

Subtracting eq3 and eq4, we get

⇒x=8

Put x=8 in eq3

⇒y=3

Hence, the speed of the boat in still water=8km\hr

The speed of stream=3km\hr

3x + 18 = 147°

step-by-step explanation:

3x + 18 = 147°, because the value of the central angle is equal to the value of the arc formed by it.

i hope i you.

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step-by-step explanation:

we can analyze the pattern at which the terms increase. let us denote , , , so that we can call

note the following:

the pattern: to get the next term value, we just add the next term number (e.g. 1st, 2nd, to the previous term value (term values are the given numbers in the question, 1, 3, 6, 10, 15,

from , to get to , we add

from , to get to , we add

etc.

we need to form a recursive formula, a formula that has the next term as a function of the previous term. so a possible recursive formula can be

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