P5 Math: Blue and Red beads

A box contained blue beads and red beads. At first, there were 5 times as many as blue beads. After 28 blue beads and 28 red beads were removed, the difference in the number of blue beads and red beads left in the box was 260.

(a) How many blue beads were there in the box at first ?

(b) What was the total number of beads left in the box ?

Solution:

Please take note that 28 beads are fewer than one unit.

One unit  = u + 28

From the model: 4 u + (4 * 28) = 260 --> u = 37

One unit = 37 + 28 = 65

By observing model above:

(a) At first there were 5 units = 5 * 65 = 325

(b) Total number of beads left in the box = 2u + 260 = 334