Let’s solve each problem step by step.
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Problem 1: Carbon in steel
We’re told:
→ 15 g of carbon is in every 1 kg (which is 1000 g) of steel.
a. How much carbon in 10 kg of steel?
If 1 kg has 15 g → then 10 kg has 15 × 10 =
150 g
✔ Answer for 1a:
150 g
b. How much steel from 600 g of carbon?
We know: 15 g carbon → makes 1000 g steel
So, how many “15 g” groups are in 600 g?
→ 600 ÷ 15 = 40
Each group makes 1000 g steel → so 40 × 1000 =
40,000 g
That’s 40 kg — but since the question doesn’t specify units, we can leave it as grams or convert. Let’s check context: original was in g and kg. Since input was 600 g, output in g is fine unless asked otherwise. But 40,000 g = 40 kg — probably better to write as
40 kg for clarity.
Wait — let’s double-check:
Ratio: carbon : steel = 15g : 1000g = 3:200
So if carbon = 600g, then steel = (200/3) × 600 = 200 × 200 =
40,000 g = 40 kg
✔ Answer for 1b:
40 kg
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Problem 2: Class going to Alton Towers
Total children = 36
Ratio boys : girls = 5 : 4
Total parts = 5 + 4 = 9 parts
Each part = 36 ÷ 9 = 4 children
Boys = 5 parts → 5 × 4 =
20 boys
✔ Answer for 2a:
20
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Problem 3: Dan and Tom share prize money
Ratio Dan : Tom = 4 : 9
Dan got smaller amount = £120 → that’s his 4 parts
So 4 parts = £120 → 1 part = 120 ÷ 4 = £30
a. Total amount won?
Total parts = 4 + 9 = 13
Total = 13 × £30 =
£390
✔ Answer for 3a:
£390
b. How much did Tom get?
Tom = 9 parts → 9 × £30 =
£270
✔ Answer for 3b:
£270
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Problem 4: Fruit picking
Ratio Leanne : Emma : Debbie = 4 : 3 : 1
Leanne picked 12 kilos → her 4 parts = 12 kg
So 1 part = 12 ÷ 4 = 3 kg
a. How much did Emma pick?
Emma = 3 parts → 3 × 3 =
9 kg
✔ Answer for 4a:
9 kg
b. Total fruit picked?
Total parts = 4 + 3 + 1 = 8
Total = 8 × 3 =
24 kg
✔ Answer for 4b:
24 kg
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Problem 5: Aeroplane passengers
Total people = 390
Adults : Children = 9 : 4
Total parts = 9 + 4 = 13
Each part = 390 ÷ 13 = 30
a. Adults?
9 parts → 9 × 30 =
270 adults
✔ Answer for 5a:
270
b. Children?
4 parts → 4 × 30 =
120 children
✔ Answer for 5b:
120
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Problem 6: Simplify ratio 91 : 63
Find greatest common factor (GCF) of 91 and 63.
Factors of 63: 1, 3, 7, 9, 21, 63
Factors of 91: 1, 7, 13, 91
Common factors: 1, 7 → GCF = 7
Divide both by 7:
91 ÷ 7 = 13
63 ÷ 7 = 9
So simplified ratio =
13 : 9
✔ Answer for 6:
13 : 9
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Final Answer:
1a. 150 g
1b. 40 kg
2a. 20
3a. £390
3b. £270
4a. 9 kg
4b. 24 kg
5a. 270
5b. 120
6. 13 : 9
Parent Tip: Review the logic above to help your child master the concept of ratios problems worksheets.