How many notes did bob and chris had ?

Question

.At first,Bob had only $5 notes and Chris had only $2 notes. The number of notes Bob had is 80 % of Chris’ notes. When Bob gives Chris $100, the number of notes Chris has now is 70 % more than Bob.

a. How many notes did Bob have at first ?

b. How much money does Chris have at the end ?

Answer 1

Say Chris had 5x notes, and so Bob had

80% of 5x notes

i.e. 4x notes.

Bob gives Chris 20*$5 = $100,

and so Chris now has 5x + 20 notes

and Bob has 4x - 20 notes.

We are told that the number of notes Chris has is 170% of the number that Bob has.

i.e. 5x + 20 = 1.7*(4x - 20)

5x + 20 = 6.8x - 34

54 = 1.8x

x = 54/1.8

.. = 30

Hence at first Chris had 5*30 = 150 notes,

Bob had 4*30 = 120 notes.

Chris now has 170 notes, 150 of them are $2 notes, total value = $300,

and 20 of them are $5 notes, total value = $100

so that altogether Chris has $400 at the end.

Bob now has 100*$5 = $500