Ivan buys 2 shirts for $12.40. Work out the cost of 6 shirts. *

6 shirts cost $37.20

Step-by-step explanation:

You first divide $12.40/2 to get the cost of a single shirt which is $6.20.  Then you multiply the cost for a single shirt by 6, to get the final answer of $37.20.

56.6

step-by-step explanation:

the ratio of the perimeters is equal to the scale.

the ratio of the areas is equal to the square of the scale.

34 / 20 = k

a / 19.6 = k²

substituting:

a / 19.6 = (34 / 20)²

a = 19.6 (34 / 20)²

a ≈ 56.6