My Last Gcse Math Question - Ever!!

[kuiperbelt]

Please see link below:

https://ibb.co/gtQzffS

[ClareTG0ld]

As your last ever, I'm going to delay the answer as long as possible so that this moment can be cherished :)

[bobbinwales]

Fraction 1 in 3 so 33.333333333.....%

[ZebuSanctuary]

This problem is perhaps best understood with the aid of a 'Tree Diagram' as shown in the link below.

https://ibb.co/BgJqcwj

The red branches have been highlighted since they are germane to the overall probability of the 2nd tile being higher in value than the 1st.

May I wish your grandson the very best of luck with his up and coming GCSE exams.

[ToraToraTora]

= 3/7*(4/7 + 5/7)
= 3/7 * 9/7
= 27/49
= 55.1%

[ToraToraTora]

why last ever?

[ZebuSanctuary]

Oops... In the interest of completeness, although not relevant to the answer, there should be another branch at the bottom showing the probabilty 1/6 of selecting a No. 10 tile in the event the first tile picked was No. 11

For some reason this was omitted. Perhaps it overstepped the bottom margin of the page and therefore not uploaded?

[bobbinwales]

Toratoratora- Zebus answer is the correct one. Well they got the same as me anyway

[ToraToraTora]

ok I think I see my error:
=((2/7) x (5/6)) + ((1/7 x 4/6)
=10/42 + 4/42
=14/42 = 33.3%

[kuiperbelt]

TTT \why last ever?\

Grandson began the first of his GCSE exams today. He is revising in other subject areas now. Yesterday he got the result of a mock math exam held last week. In previous math tests he had only managed low 50% scores.

We were overjoyed to learn he had score scored 81%. A massive improvement and the right reward for the hard work he put in over the last 5/6 weeks. Just hope he can produce similar performance in the 3 GCSE papers, Paper 1 being this Friday. Therefore let me once again thank all posters for there assistance in answering the GCSE questions I have posted on AB on his behalf!!

[kuiperbelt]

Spot on Zebu, BA to you.

Sorry bobbin but grandson needed to know how the answer was arrived at!!

[Aberrant1]

Why are you talking to yourself?

[Tilly2]

Well done Grandpa!

[ToraToraTora]

18:05, so it'll be partly "our" GCSE!

[ClareTG0ld]

// We were overjoyed to learn he had score scored 81%. A massive improvement and the right reward for the hard work he put in over the last 5/6 weeks.//

Wonderful!

[ToraToraTora]

Interesting that I did get the answer on my second attempt but used only arithmetic rather than the tree diagram.