Q&A - P5 Math

[tianzhu]

shann2:

Daniel had four times as many toy cars as Jeremy at first. The two boys then bought the same number of toy cars each. After that, Jeremy had 54 toy cars, which was half the number of toy cars Daniel had. Find the number of toy cars each boy had at first. [4m]

Hi

Due to time constraints, I'll not draw the MD.

At first

Daniel had four times as many toy cars as Jeremy at first.

Daniel ------ 4 units
Jeremy ------ 1 unit
Difference ------ 3 units

The two boys then bought the same number of toy cars each.

Since the two boys bought the same number of toys each, the difference in the number of toys between Daniel and Jeremy stays the same.

After that, Jeremy had 54 toy cars, which was half the number of toy cars Daniel had.

3 units ------ 54
1 unit ------ 18

Daniel@first ------ 4*18 ------ 72
Jeremy@first ------ 18

Best wishes

[tianzhu]

shann2:

Jolly and Pauline spent $1 450 altogether on Christmas gifts while Harry and Jolly spent $2658 altogether. If Harry spent thrice as much as Pauline, how much did Jolly spend? [4m]

Hi

You may solve it pictorially, using letters of the Alphabet or Units Parts.

J + P ------ 1450

J + H ------ 2658

J + PPP ------ 2658 (If Harry spent thrice as much as Pauline?)

PP ----- 2658 – 1450 ------ 1208

P ------ 604

J ------ 1450 – 604 ------ 846

Best wishes

[shann2]

Thanks tianzhu for the quick reply. Understood your solution! Thanks a lot !

[Jamesbond]

tianzhu:

Jamesbond:

Another one....an MCQ...

It takes 3 cleaners 2/9 h to clean an office. How long do 5 cleaners take to clean the same office, assuming every cleaner clean at the same time?
1) 2/3h
2) 2/15h
3) 2/27h
4) 10/27h.....

Hi

3 cleaners ------ 2/9

1 cleaner ------ 2/9*3 ------ 6/9 ------ 2/3h

5 cleaners ------- 2/3*1/5 ------ 2/15h

Best wishes

:thankyou:

[Jamesbond]

Sulin has a picture measuring 51/5 cm by 5 cm. she wants to paste the picture on a cardboard leaving a border of 2 cm around the picture. What is the area of the border?

Pl help?

[tianzhu]

Jamesbond:

Sulin has a picture measuring 51/5 cm by 5 cm. she wants to paste the picture on a cardboard leaving a border of 2 cm around the picture. What is the area of the border?

Pl help?

Hi

It helps to start with a simple diagram.

Area of picture ------- 5.2*5 ------ 26

Area of cardboard ------ 9.2*9 ------ 82.8

Area of border ------- 82.8 – 26 ------- 56.8

Best wishes

[elisammom]

Pls help


Siva has a rectangular cardboard measuring 24 cm by 15 cm. what is the maximum number of squares of sides 6 cm that he can cut from the cardboard.
Ans given is 8. Y not 10?
24*15= 360
360/36= 10

Pls help to explain. TIA

[BigDevil]

The 24 cm side can fit exactly 4 6cm squares, but the 15 cm

side can only fit 2, with an excess of 3cm.

Total number of 6cm squares ----- 4 x 2 = 8

[elisammom]

Thanks! I got it;)

[elisammom]

Another question, pls help


There were 44 pupils in a class. 34 pupils passed science and 36 pupils passed english. 4 pupils did not pass both subject. How many pupils passed both subjects?
Ans is 30.

Tia