PSLEThe graph shows the mass of a glass when empty and when different combinations of objects B, C and D are placed in the glass.
- What is the mass of the empty glass?
- What is the average mass of the objects B, C and D?
(a)
Mass of the empty glass = 180 g
(b)
Mass of B and D
= 400 - 180
= 220 g
Mass of B and C
= 440 - 180
= 260 g
Mass of C and D
= 420 - 180
= 240 g
(B + D) + (B + C) + (C + D) = 220 + 260 + 240
2 B + 2 C + 2 D = 720
2 x (B + C + D) = 720
B + C + D
= 720 ÷ 2
= 360 g
Average mass of the objects B, C and D
= 360 ÷ 3
= 120 g
Answer(s): (a) 180 g; (b) 120 g