Q&A - PSLE Math

[MathIzzzFun]

jarenchuatw:

Need help with these 2 questions

1. Ali sold some comics and kept 3/8 of the remainder for Raja and May and donated the rest. If the number sold was twice the number donated, what fraction of the comics was sold?

2. John bought more than 10 chickens and ducks for $69. One duck cost $8, and one chicken cost$5. Find the number of chickens bought

Hi

Q1.
remainder --> 8u
donated --> 5u
sold --> 10u
total --> 10u + 8u = 18u
fraction of comics sold = 10/18 = 5/9

Q2.
Use G&C.
Given more than 10 chickens and ducks. So, need to find total number N, such that (8N-69) is a multiple of 3
N=11, 8x11-69 =19 X
N=12, 8x12-69 =27 v --> number of chickens = 27/3 = 9

Number of chickens = 9
Number of ducks = 3

cheers.

[MathIzzzFun]

duplicate

[peggy]

Please help :


1. Nathan and Peter went shopping with a total sum of $60. Nathan spent twice as much as Peter. The amount Peter had left with was $7 more than what he spent. He had twice as much money left as Nathan. How much money did Nathan have at first ?

2.an equal number of men and women were at a party. The ratio of the number of woman who wore watches to the number of men who wore watches was 3:11. The ratio of the number of women to the number of men who did not wear watches was 5:3.

A. Find the ratio of the number of women who wore watches to the number of women who did not wear watches.

B. When 7 times as many men as women left the party, the ratio of the number of men to the number of women who remained at the party became 35:38. If 560 men remained at the party, how many men left the party?

Many thanks.

[MathIzzzFun]

peggy:

Please help :


1. Nathan and Peter went shopping with a total sum of $60. Nathan spent twice as much as Peter. The amount Peter had left with was $7 more than what he spent. He had twice as much money left as Nathan. How much money did Nathan have at first ?


Many thanks.

Q1.
Peter's money, spent --> 2 units
Peter's money, left --> 2 units + 7
Nathan's money, left --> 1 unit + 3.5
Nathan's money, spent --> 4 units
Total amount --> 9 units + 10.5 = 60
1 unit --> 5.5

Nathan's money at first = spent + left = $(5 x 5.5 + 3.5) = $31

cheers.

[peggy]

MathIzzzfun,


Got it. Thanks again and good night !

[MathIzzzFun]

peggy:

Please help :

2.an equal number of men and women were at a party. The ratio of the number of woman who wore watches to the number of men who wore watches was 3:11. The ratio of the number of women to the number of men who did not wear watches was 5:3.

A. Find the ratio of the number of women who wore watches to the number of women who did not wear watches.

B. When 7 times as many men as women left the party, the ratio of the number of men to the number of women who remained at the party became 35:38. If 560 men remained at the party, how many men left the party?

Many thanks.

Q2.
a)
wearing watches, women : men = 3 : 11 (difference of
not wearing watches, women : men = 5:3 (difference of 2)
--> difference must be the same since equal number of men and women

wearing watches, women : men = 3u : 11u
not wearing watches, women : men = 20u : 12u
women wearing watches : women not wearing watches = 3:20

b)
number who left the party, men : women = 7u : 1u, difference = 6u

difference in number of men and women who remained at the party
= 3/35 x 560 = 48

6u --> 48
1u --> 8,
Number of men who left the party = 7 x 8 = 56

cheers.

[peggy]

MathIzzzfun,


Wow ! That’s Fast, your quick response is much appreciated.

Thanks!!!

[peggy]

please assist.


Ken left Sunny Town at 10 40 for Merry Town at an ave speed of 48km/h. At 12 00 Sam left Sunny Town and traveled towards Merry Town at an ave speed of 80km/h. After overtaking Ken, Sam took another 4h 12 min to reach Merry Town.

a) at what time did Sam overtake Ken ?
B) how far away was Sam from Merry Town when Ken was 264 km away from Merry Town ?

thanks.

[tianzhu]

peggy:

please assist.


Ken left Sunny Town at 10 40 for Merry Town at an ave speed of 48km/h. At 12 00 Sam left Sunny Town and traveled towards Merry Town at an ave speed of 80km/h. After overtaking Ken, Sam took another 4h 12 min to reach Merry Town.

a) at what time did Sam overtake Ken ?
B) how far away was Sam from Merry Town when Ken was 264 km away from Merry Town ?

thanks.

Hi

Hope this helps.

Best wishes

http://farm9.staticflickr.com/8146/7554794486_e5b2ed720e_z.jpg\">

[peggy]

Tianzhu,


thanks for replying with very clear illustrations.