Answer: 10
<u>Step-by-step explanation:</u>
varies directly means: 
Step 1: solve for k ⇒ 
Step 2: plug in the given value and k to solve for the missing value: 
42(5) = 21(x)

2(5) = x
10 = x
Step-by-step explanation:
hop it help ..........
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Answer:
do you still need this answered?
Step-by-step explanation:
If 3/5 of the tree is unripe, then 2/5 of the tree is ripe.
2/5 = 0.4
0.4 x 100 = 40% of the tree is ripe
I think you shouldn't memorize any formula to solve it. But you should know that on the fahrenheit thermometer freezing point is 32 and the boiling point is 212. And in celcius, it is 0 and 100. So we can make the inference that changing 100 units in celcius corresponds to a change of 180 units in fahrenheit. Thus, we should ask that if celcius increase from 0 to 200, what would happen to fahrenheit.
Basic math:
While celcius increase 100, fahrenheit increase 180,
While celcius increase 200, fahreinheit increase 360.
And you shouldn't forget that fahrenheit's freezing point is 32.
32+increase(360)=392