## Question

primary 6 | Maths | Ratio

Anyone can contribute an answer, even non-tutors.

##### Yvonne Chong

chevron_right chevron_right chevron_right

Actually not ratio but a random question. Like to horoscope booklets with questions that doesn't mks my sense. Pls help. I still got more questions to ask cause Idk. Help plss. Thanks in advance

Date Posted: 1 month ago
Views: 15
J
1 month ago
Amount she paid for 2kg of sugar from shop A = \$0.90 x 2 = \$1.80

Since the average she paid was only 78 cents per kg,

\$0.78 x 2 = \$1.56

\$1.80 - \$1.56 = \$0.24

We can see this as \$0.24 was transferred from the cost of sugar bought from shop A to the cost of sugar from shop B,to make the cost 'go up' from 70 cents to 78 cents per kg.

\$0.78 - \$0.70 = \$0.08

\$0.24 ÷ \$0.08 = 3

So 3 kg of sugar was bought from shop B.

(Check :

Actual cost of sugar from shop B
= 3kg x \$0.70per kg
= \$2.10

Total cost of sugar from both shops
= \$2.10 + \$1.80
= \$3.90

Average cost of sugar = \$3.90 ÷ (2kg +3kg)
= \$3.90 ÷ 5kg
= \$0.78 per kg