## Q&A - PSLE Math

Can someone help to solve this question. TIA.

James had some fishes in a tank. 15 were goldfish and the rest were guppies and angelfish.

The ratio of the number of goldfish to the number of guppies was 3:2 and the ratio of the number of guppies to the number of angelfish was 1:5. If James added 24 fish into the tank, the number of guppies would increase by 50%, and the angelfish would increase by 40%.

How many goldfish were added?

P/S: My girl told me that the question got mistake, please see if you can solve it. Question from school with no answer provided.

- David Koriadi
- KiasuNewbie
**Posts:**7**Joined:**Sun Jul 06,

- 3greatkids
- OrangeBelt
**Posts:**58**Joined:**Mon Jul 20,

a) John's age now is (36-n)/2.enoawng wrote:can anyone help?

John was n years old when his mother was 36 years old. Today, his mother is 3 times as old as John.

a) Express John’s age now in terms of n

b) What is John’s age now if n=8?

The theory is that the difference between mother's age and john's age never change, therefore, the difference in their age is always 36-n.

In order for the mother to be 3 times as old as John, when u draw the model, John will be 1 unit whereas mum is 3 units. their age difference(36-n) will then take up 2 units and john's age would be 1 unit. so in order to find 1 unit, you will take (36-n)/2

b) thus john's age now is (36-8)/2 which is 14

### easy and common question

Question asked:

Mary and Peter attended a party. Peter met with 4 times as many boy as girls while Mary met with 5 times as many boys as girls. How many boys and girls were at the party?

Mary and Peter attended a party. Peter met with 4 times as many boy as girls while Mary met with 5 times as many boys as girls. How many boys and girls were at the party?