Now that we have looked at what ratios are and how to simplify them, let’s look at problem sums on ratios.
Pasir Ris Secondary School Mid Year Paper – 2017 Q12
Worked Solutions
(a) Megan’s Contribution = \( \frac{270}{3+2+4} \times 2 \) = $60
(b)(i) Eunice’s initial contribution = \( \frac{270}{3+2+4} \times 3 \) = $90
Eunice’s contribution now = $90 x 2 = $180
Megan’s Contribution now = $60/2 = $30
Shannon’s contribution now = $270 – $180 – $30 = $60
(ii) New Contribution ratio of Eunice: Megan: Shannon
= 180: 30:60
= 6: 1: 2
Chung Cheng High School Mid Year Paper – 2017 Question 12
Worked Solutions
(a) Weight of baking powder = \( \frac{60}{4} \times 14 \) = 210 g
(b) 3.5 h = 3. 5 x 60 x 60 s = 12 600 s
Mass of baking powder filled in 12 600 s = 12600 x 180 = 2268000 g = 2268 kg
Number of bags of baking powder filled = 2268 / 1.5 = 1512
** Note: (b) is not a ratio question