<h2>
Answer:</h2>
The equation that he could be used to solve the problem is:
5n+30n+50n=340
<h2>
Step-by-step explanation:</h2>
If n represents the number of nickels Janet has.
Hence n nickels=0.05n dollars.
Then the number of dimes he has is: 3n
( Since, Janet has three times as many dimes as nickels )
Also, 1 dime=0.10 dollars
Hence, 3n dime= 0.30n dollars)
and the number of quarters he has is: 2n
(He has twice as many quarters as nickels
Also, 1 quarter=0.25 dollars
Hence, 2n quarter=0.50n dollars. )
Hence, we have ,
0.05n+0.30n+0.50n=3.40
On multiplying both side of the equation by 100 we have:
5n+30n+50n=340