Question

In autumn a tree starts to shed its leaves. 2/5 of the leaves fall off in the first week. 1/2 of those remaining fall of in the second week, and 2/3 of those remaining fall of in the third week. 85 leaves now remain.

Answer 1

Answer:

850 leaves were on the tree initially.

Same as;

2/5 + 1/5 + 3/10 + (remaining leaves 1/10) = 1

4/10 + 2/10 + 3/10 + 1/10

10 x 85 = 850

Step-by-step explanation:

2/5  wk 1 fall off

1/5  wk 2 fell off

3/5 x 1/2  = 3/10 wk 2 stayed on tree

1/3 x 3/10 = 1/10 wk 3 stayed on

2/5 + 1/5 + 3/10 = 9/10 =  0.9 fall off in total

10/10 - 9/10 = 1/10 left on tree

1/10 = 85

10 x 85 = 850 leaves.