Maths problem.. please help

suffolkb

Oops. I have assumed it`s a right angled triangle, which was not stated in the question. As written, the question cannot have a unique answer.

scottishlass

Is 10b 2 to the power six? If so the answer would be 64.

Also x^2+3=25 would give x^2 = 25 - 3
= 22
So x would be 4.49 but as your not allowed calculators. I would have put square root of 22 as you cant cancel that down anymore (well I dont think you can)

bristol_pilot

8a is impossible as-written. The question does not state that the triangle contains a right angle. Even if it did, you still need to be told which side it is that you need to find the length of.

I suspect that it means a right-angled triangle of sides 3, 4 and 5.

Whoever set this test needs to go on a course themselves (on quality control in setting exams).

scottishlass

6) a brass nail is 8:1 for copper and tin

a-if the total weight of the nail is 18g what was the weight of the copper in the nail?
14.8g?

b- if the tin in the nail is 1.5g what is the total weigh of the nail?
8.46g?

a) If the ratio is 8:1 you divide 18 by (8+1) and then multiply by 8 to get the copper weight so 18/9 = 2 multiply by 8 gives you 16g

b) For the total weight of the nail when you know the tin is 1.5g you multiply this by (8+1) to get 13.5g

bristol_pilot

Question 6 is also nonsense. If the ratio of copper:tin is 8:1 and the total weight of the nail is 18g, then it must contain 16g copper and 2g tin.

How can the total weight or the tin content of the same nail be different in the second part of the question? Maybe they mean another nail made of the same material, but that's not what it says.

The examiner should go back to school!

bristol_pilot

Question 10a:

The square root of 27 is indeed 5.196, but it is a tall order to work this out without a calculator or tables and I suspect the examiner meant to ask for the cube root, which is 3.

scottishlass

bristol_pilot wrote: »

Question 10a:

The square root of 27 is indeed 5.196, but it is a tall order to work this out without a calculator or tables and I suspect the examiner meant to ask for the cube root, which is 3.

Or they would expect to you cancel it down ie.

squareroot(27) = squareroot(9) x squareroot(3)
= 3 x squareroot(3)

Hope that makes sense

retepetsir

Well, I wish you good luck for the retake....

my missus is about the qualify and managed to pass the exam first time.

I hope for the future that you can get the drug calculations right, as it's quite important!

bristol_pilot

What is this a test for?

Broke_Student

scottishlass wrote: »

a) If the ratio is 8:1 you divide 18 by (8+1) and then multiply by 8 to get the copper weight so 18/9 = 2 multiply by 8 gives you 16g

b) For the total weight of the nail when you know the tin is 1.5g you multiply this by (8+1) to get 13.5g

I thought the 8:1 would be a molar ratio and to work out the ratio of mass you would have to multiply the molar ratios by the relative atomic masses of the respective elements. Thats what I tried to work out anyway. The question isn't clear about what the 8:1 means (mass or moles).