In 20 years mary will be three times as old as she is now. how old is she now?

Mary is 10 yrs old now.

Explanation:

10+20=30

30÷3=10

So, Mary has to be 10yrs old now.

296 ft²

Step-by-step explanation:   5 18 7 20

There are a few ways to calculate the area of the tihis composit figure.

The one way is to calculate the entire area of the big rectangle with the voided area and substract the smaller voided rectangle

Big rectangle with voided area  

26 × 16   = 26 × 10 + 26 × 6 =  260 + 156 =  416

Small Void Rectangle = 6 × (26 - 2 - 4)

                                    = 6 × 20

                                    = 120

Total area = Big rectangle with voided area - Small Void Rectangle

                 =   416 - 120

                 =  296 ft²

another way is to add up three areas

large filled rectangle +  smaller filled rectangle +  smallest filled rectangle

        10 × 26  +  4 × 6 + 2 × 6

           260 + 24 + 12

                296 ft²