PSLE
Wendy and Opal each had a plate of dough of the same mass for making sandwiches. The same mass of dough was used for each sandwich. Wendy made 30 sandwiches and had 400 g of dough left. Opal made 16 sandwiches and had 1.03 kg of dough left.

1. What was the mass of dough needed for each sandwich?
2. With the remaining dough from both girls, how many more such sandwiches can be made at most? 

(a)
Difference between the number of sandwiches made by Wendy and Opal
= 30 - 16
= 14

1 kg = 1000 g
1.03 kg = 1.03 x 1000 = 1030 g

Difference between the remaining dough left by Opal and Wendy
= 1030 - 400
= 630 g

Mass of 14 sandwiches = 630 g

Mass of 1 sandwich
= 630 ÷ 14
= 45 g

(b)
Total remaining dough left
= 1030 + 400
= 1430 g

Sets of 45 g
= 1430 ÷ 45
= 31 r 35

Number of sandwiches = 31

Answer(s): (a) 45 g; (b) 31