Q&A - PSLE Math

[tianzhu]

jonaandr:

1. The ratio of the number of boys to the number of girls was 4:1 for Primary 6A and the ratio of the number of boys to the number of girls was 2:3 for Primary 6B.Both classes had the same number of pupils. After 4 girls left Primary 6A to join Primary 6B, the ratio of the number of boys to the number of girls in Primary 6B became 4:7. How many boys were there in Primary 6A?

Hi

Consider 6B first.

At first

Boys:Girls -------- 2u:3u

Change

Boys:Girls -------- 0 :+4

In the end

Boys:Girls -------- 4p:7p

2u ----- 4p

(x7)
14u ------ 28p

3u + 4 ------ 7p

(x4)
12u + 16 ------- 28p

14u ------- 12u + 16

1u ------- 8

Number of girls in 6B ------ 5*8 ------ 40.

Number of boys in 6A ------ 4/5*40 ------- 32

Best wishes

[Winx5015]

Hi, can anyone help me with the following questions?


http://i49.tinypic.com/2hnqkyc.jpg\">

:thankyou:

[Winx5015]

http://i46.tinypic.com/2wqstwy.jpg\">

[Winx5015]

http://i48.tinypic.com/k054s7.jpg\">

[tianzhu]

Winx5015:

Hi, can anyone help me with the following questions?


http://i49.tinypic.com/2hnqkyc.jpg\">

:thankyou:

Hi

Angle AEC ------ 36

AngleCED -------- 54

Angle KEF --------- 54 (opposite)

Angle EKF --------- 180 –(54+54) --------72 (isosceles)

Angle FGH ---------- 180 -54 ------ 126 (parallelogram)

Angle KFG ---------- 126 (angle on a straight line)

Sum ------- 252

Best wishes

[Robertpattinsonidle]

tianzhu:

Winx5015:

Hi, can anyone help me with the following questions?


http://i49.tinypic.com/2hnqkyc.jpg\">

:thankyou:

Hi

Angle AEC ------ 36

AngleCED -------- 54

Angle KEF --------- 54 (opposite)

Angle EKF --------- 180 –(54+54) --------72 (isosceles)

Angle FGH ---------- 180 -54 ------ 126 (parallelogram)

Angle KFG ---------- 126 (angle on a straight line)

Sum ------- 252

Best wishes

[Robertpattinsonidle]

tianzhu:

Winx5015:

Hi, can anyone help me with the following questions?


http://i49.tinypic.com/2hnqkyc.jpg\">

:thankyou:

Hi

Angle AEC ------ 36

AngleCED -------- 54

Angle KEF --------- 54 (opposite)

Angle EKF --------- 180 –(54+54) --------72 (isosceles)

Angle FGH ---------- 180 -54 ------ 126 (parallelogram)

Angle KFG ---------- 126 (angle on a straight line)

Sum ------- 252

Best wishes

which paper is this from? Thank you.

[tianzhu]

Winx5015:

http://i46.tinypic.com/2wqstwy.jpg\">

Hi

A quick one, got to go.

Angle p ------ 180 - 90 - 30 ------- 60

Best wishes

[tianzhu]

Winx5015:

http://i48.tinypic.com/k054s7.jpg\">

Hi

Row 7 --------- 13*14 ------- 182

Row 35 -------- 69*70 -------- 4830

Row 23 -------- 45*46 -------- 2070

Best wishes

[Winx5015]

Hi Robertpattinsonidle,


This is a prelim practice paper given by my teacher. As for from which school, not sure.