The graph shows the number of postcards 3 students collected. Study the graph and answer the following.
- Who collected 21 postcards? Give the answer in number. (Eg 1)
- Which 2 students collected a total of 39 postcards? Give the answer in numbers. (Eg 1, 2)
- How many postcards must Mary give to Molly so that both of them would have the same number of postcards?
(a)
3 postcards → 1 triangle
21 postcards → 21 ÷ 3 = 7 triangles
(2) Emily has 7 triangles so she collected 21 postcards.
(b)
Total number of triangles represented by 39 postcards
= 39 ÷ 3
= 13
Number of triangles that Emily and Molly had
= 7 + 6
= 13
2 students who collected a total of 39 postcards are (2) Emily and (3) Molly.
(c)
Difference in the number of triangles that Mary and Molly had
= 8 - 6
= 2
Number of postcards that Mary must give to Molly
= 2 ÷ 2 x 3
= 3
Answer(s): (a) 2; (b) 2, 3; (c) 3