Priya, Quinn and Raj share 720 marbles in the ratio 3 : 4 : 5. How many more marbles does Raj receive than Priya?
Need a hint?
Find the value of one part first, then compare the difference in parts between Raj and Priya.
Worked answer
- Total parts = 3 + 4 + 5 = 12.
- One part = 720 ÷ 12 = 60 marbles.
- Raj has 5 parts = 300 marbles; Priya has 3 parts = 180 marbles.
- Difference = 300 − 180 = 120 marbles (or 2 parts = 2 × 60 = 120).
Answer: 120 marbles
The mistake this question tests
Habit
Stopped at one part in ratio
Pupils often divide 720 by 3 or by 5 and then subtract, instead of finding the total number of parts (12) first.
How to fix it at home →Wrong answers children often give:
- 60 Stopped at one part in ratio
- 300 Calculation slip
More PSLE ratio questions
Short answer · 2m
The ratio of boys to girls in a class is 3 : 5
See the answer →Structured · 3mPriya and Marcus had some stickers each
See the answer →MCQ · 2mPoints P, Q, R, S and T lie in that order on a straight path
See the answer →Short answer · 2mOn Arun's town map, 3 cm represents 15 km
See the answer →Structured · 4mA box contains red and blue beads
See the answer →MCQ · 2mIn a park, the ratio of the number of trees in Garden P to the number of trees in Garden Q is 3 : 5
See the answer →Practise PSLE ratio until the mistakes stop.
Three PSLE questions, free, no sign-up. You’ll see exactly where the marks went. Then 7 days of everything for S$4.99.