Suppose you want to fill nine 1lb. tins with a snack mix . you have 15$ and plan to buy almonds for 2.45$ per lb hazelnuts for 1.85$ per lb and raisins for 0.80$ per lb you want the snack mix to contain twice as much of almonds plus hazelnuts as raisins by weight . how much of each ingredient should you buy ?

check the picture below.

distance covered by pamela in 9 l of fuel = 99km

let us apply unitary method here.

distance covered by pamela in 1 l of fuel =99/9 =11 km

now let us find distance covered by pamela if she has 12 l of fuel.

distance covered in 12 l = distance covered in 1 l of fuel * 12

we know that distance covered by here in 1 l is 11 km.

so distance covered in 12 l of fuel = 11*12 = 132 km.

the mistake in the pattern is that :

b. the decimal point was moved one too many place values each time

the correct pattern could be made by :

b. moving the decimal point to the right the same numbers of place values as the exponents