## Q&A - PSLE Math

### Re: Q&A - PSLE Math

Ali is 30 yrs old now. His father is 65 years. How many years ago was his father 5 times as old as him?

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- BrownBelt
**Posts:**559**Joined:**Mon Oct 12,**Total Likes:**3

### Re: Q&A - PSLE Math

Hi,lulu2014 wrote:Ali is 30 yrs old now. His father is 65 years. How many years ago was his father 5 times as old as him?

Please check the numbers again.

.

### Re: Q&A - PSLE Math

please help.

At 11.00 a.m. Justin drove from Town S to Town T at an average speed of 70km/h. At the same time, Terry set off from Town T towards Town S. Some time later, they passed each other and were 10 km apart at 2 p.m. Justin arrived at Town T at 4 p.m.

a) Find the average speed of Terry.

b) Find the time at which Terry arrived at Town S.

TIA

At 11.00 a.m. Justin drove from Town S to Town T at an average speed of 70km/h. At the same time, Terry set off from Town T towards Town S. Some time later, they passed each other and were 10 km apart at 2 p.m. Justin arrived at Town T at 4 p.m.

a) Find the average speed of Terry.

b) Find the time at which Terry arrived at Town S.

TIA

### Re: Q&A - PSLE Math

Hi, ps help..Many tks n God Bless:)

There are 20 questions in a Maths quiz. 5 marks were given for each correct answer. 2 marks were deducted for each wrong answer. Cindy answered all the questions and scored 65 marks. How many questions did she answer correctly?

There are 20 questions in a Maths quiz. 5 marks were given for each correct answer. 2 marks were deducted for each wrong answer. Cindy answered all the questions and scored 65 marks. How many questions did she answer correctly?

### Re: Q&A - PSLE Math

This is heuristics guess and check question. By tabulation. Draw +5 column and a -2 column. Then fill in 2 numbers which add up to 20 under each column. Answer is 15x5 - 5x2 =65.SOS mum wrote:Hi, ps help..Many tks n God Bless:)

There are 20 questions in a Maths quiz. 5 marks were given for each correct answer. 2 marks were deducted for each wrong answer. Cindy answered all the questions and scored 65 marks. How many questions did she answer correctly?

- Kangkangteo
- BlueBelt
**Posts:**345**Joined:**Sun May 11,**Total Likes:**1

### Re: Q&A - PSLE Math

20 x 5 = 100Ninjago wrote:This is heuristics guess and check question. By tabulation. Draw +5 column and a -2 column. Then fill in 2 numbers which add up to 20 under each column. Answer is 15x5 - 5x2 =65.SOS mum wrote:Hi, ps help..Many tks n God Bless:)

There are 20 questions in a Maths quiz. 5 marks were given for each correct answer. 2 marks were deducted for each wrong answer. Cindy answered all the questions and scored 65 marks. How many questions did she answer correctly?

100 - 65 = 35

- 5 - 2 = - 7

35/7 = 5 wrong answers

20 - 5 = 15 correct answers (ans)

- Kangkangteo
- BlueBelt
**Posts:**345**Joined:**Sun May 11,**Total Likes:**1

### Re: Q&A - PSLE Math

From 2 p.m. to 4 p.m. ---> 2 hhtn wrote:please help.

At 11.00 a.m. Justin drove from Town S to Town T at an average speed of 70km/h. At the same time, Terry set off from Town T towards Town S. Some time later, they passed each other and were 10 km apart at 2 p.m. Justin arrived at Town T at 4 p.m.

a) Find the average speed of Terry.

b) Find the time at which Terry arrived at Town S.

TIA

70 x 2 = 140 km

From 11 a.m. to 2 p.m. ---> 3 h

140 + 10 = 150 km

150/3 = 50 km/h (ans a)

70 x 5 = 350 km

350/50 = 7 h

7 h after 11 a.m. ---> 6 p.m. (ans b)

### Re: Q&A - PSLE Math

thanks PiggyLaLa!PiggyLalala wrote:Refer to the diagram,isetan wrote:Hi kangkangteo,

Under your explanation of bases and height, but how does that equate to the area in the shaded portion?

Area A + area B + 246 = 1/2 area of rectangle ABCD

Area A + area B + shaded area = 1/2 area of rectangle AND

therefore shaded area = 246