A company that sold fish for an aquarium had a special one weekend on tetras and angel fish. The store sold a total of 110 of those types of fish over the weekend. The tetras each sold for $0.40 and the angel fish each sold for $1.20. If they made a total of $80 in selling those fish, how many tetras did they sell?

They sold 65 tetras.

Step-by-step explanation:

Let x= Number of tetras

y= Number of angel fish.

As per given,

x+y= 110                  (i)

0.40x+1.20y=80         (ii)

Multiply 2.5 on both sides of (ii), we get

x+3y=200        (iii)

Eliminate (i) from (iii)

Put value of y in (i)

Hence, they sold 65 tetras.

the total estimated nappy use.=10,500,000

step-by-step explanation:

given that on an average the average baby uses 3528 napkins.

in a particular year 2014, the number of births were 299697 in new south wales.

rounding off the number of births to the nearest hundred thousand we have

no of birtsh = 300000

also rounding off the average usage to nearst thousand we get

average use of a baby = 3500

hence total number of nappy estimated to be used = 3500x300000

= 10,500,000

answer is 10,500,000 nappies