## Q&A - PSLE Math

- Crazyberry
- YellowBelt
**Posts:**10**Joined:**Sun Sep 06,

### Re: Q&A - PSLE Math

Hello

Need help again. Tq.

John is k years old. His father is 4 times as old as him. His mother is 3 years younger than his father. in how many years' time will John's father be twice as old as John. Give your answer in terms of k.

Need help again. Tq.

John is k years old. His father is 4 times as old as him. His mother is 3 years younger than his father. in how many years' time will John's father be twice as old as John. Give your answer in terms of k.

### Re: Q&A - PSLE Math

is that the complete question?Crazyberry wrote:Hello

Need help again. Tq.

John is k years old. His father is 4 times as old as him. His mother is 3 years younger than his father. in how many years' time will John's father be twice as old as John. Give your answer in terms of k.

Why is the mother even mentioned?

If it is then answer is k years

**Edited - Opps sorry wrong answer. pls see Big D and Ender's solution below.**

Last edited by Sun_2010 on Thu Mar 03, 2016 10:16 am, edited 1 time in total.

- Crazyberry
- YellowBelt
**Posts:**10**Joined:**Sun Sep 06,

### Re: Q&A - PSLE Math

There are 2 questions. 1st question is how old is John's mother? I got the answer (4k-3). But I am stuck at question 2. Answer given on answer sheet is 2k years time. I have no idea how to get it.

### Re: Q&A - PSLE Math

Currently,

John is k years old.

Father is 4k years old.

A difference of 3k years.

After some years,

John's age is 1u, father is 2u

Since difference is constant, 2u - 1u = 3k

So 1u = 3k.

Minus his current age, 3k - k = 2k

So in 2k years, John will be 3k yo, and father will be 6k yo.

John is k years old.

Father is 4k years old.

A difference of 3k years.

After some years,

John's age is 1u, father is 2u

Since difference is constant, 2u - 1u = 3k

So 1u = 3k.

Minus his current age, 3k - k = 2k

So in 2k years, John will be 3k yo, and father will be 6k yo.

### Re: Q&A - PSLE Math

Current age,Crazyberry wrote:There are 2 questions. 1st question is how old is John's mother? I got the answer (4k-3). But I am stuck at question 2. Answer given on answer sheet is 2k years time. I have no idea how to get it.

John = K,

Father =4K

Let the years forward ahead when Father's age is twice of John be 'u' years

John will be K+u

Father will be 4K + u

By then Father is twice of John's age, therefore the equation is

4K + u = 2(K + u)

4K + u = 2K + 2u

2K = u

The number of years ahead when Father will be twice of John's is 'u' years or '2K' years.

- Crazyberry
- YellowBelt
**Posts:**10**Joined:**Sun Sep 06,

### Re: Q&A - PSLE Math

Hi sun_2010, bigdevil, ender

Tq for replying. I will go over the solutions given. P6 maths is really very difficult

Tq for replying. I will go over the solutions given. P6 maths is really very difficult

### Re: Q&A - PSLE Math

Need some help in the following questions.

Q1

Using branching, I got

Gold: sliver : copper

32 : 40. : 18.

I got the answer 3300. Is it correct?

Q2.

Got a decimal number for green.

Anyone can help?

Thanks

Q1

Using branching, I got

Gold: sliver : copper

32 : 40. : 18.

I got the answer 3300. Is it correct?

Q2.

Got a decimal number for green.

Anyone can help?

Thanks

- EconsPhDTutor
- OrangeBelt
**Posts:**39**Joined:**Sat Jan 23,**Total Likes:**1

### Re: Q&A - PSLE Math

The answer to the first question (gold, silver, copper coins) is 270. Please see this PDF for the full solution.ozora wrote:Need some help in the following questions.

The answers to the second question (Jason's marbles) are (a) 60; and (b) 14.3%. Please see this PDF for the full solution.

www.EconsPhDTutor.com

Last edited by EconsPhDTutor on Sat Mar 05, 2016 7:23 pm, edited 1 time in total.

### Re: Q&A - PSLE Math

I try. Let me know if my ans is correct or not.

Red ->3u x 7 -> 21u

Green + Blue ->2u x 7 -> 14u

Green : Blue

9 : 5 ->14u

21u - 5u -> 192

u ->12

21u -> 21x12 =252

70% ->252

1%->252÷70=3.6

30%-> 3.6×30 = 108

14u -> 14x12= 168

168-108=60

a) 60

Total 35u x 12 =420

60÷420x100= 14.3%

b)14.3%

Red ->3u x 7 -> 21u

Green + Blue ->2u x 7 -> 14u

Green : Blue

9 : 5 ->14u

21u - 5u -> 192

u ->12

21u -> 21x12 =252

70% ->252

1%->252÷70=3.6

30%-> 3.6×30 = 108

14u -> 14x12= 168

168-108=60

a) 60

Total 35u x 12 =420

60÷420x100= 14.3%

b)14.3%