Answer:Jack is 9 and the father is 43
The least is 0,015
hope this will help you
Answer:d=18FT
Step-by-step explanation:
YOUR WELCOM :)
It depends on what you are trying to calculate but the most common way I go to find percentage is to multiply by the number in decimal for ie. 50% = .5.
If you are looking for a way to do it quickly in your head I always take find out what 10% is like in the case of 100 it would be 10 so if I want to find 15% I know I can find 10% and if I cut what 10% is in half I will find 5% so likewise if I add what 10%+5% I will end up with 15%. For example, 10% of 100 is 10 half of 10 is 5 and 10+5 equals 15. If you need to find something like 20% or 30% I know that I can find 10% and instead of dividing(cutting it in half) I can multiply by 2 or 3. 10% + 10% =20%
I hope it helps, if you have more questions let me know!
Answer:
120 liters of 60% alcohol solution is needed
Step-by-step explanation:
Let's assume
x liters of 60% alcohol solution is added
so, we get solution as


we are given
40 liters of a 20% alcohol solution is



so, total alcohol solution is

now, we can find total solutions
total solutions is

now, it is making 50% solution
so, we get

now, we can solve for x




So,
120 liters of 60% alcohol solution is needed