A sum of money at simple interest amounts to 815 in 3 years and to 854 in 4 years. The sum is:

Step-by-step explanation:

So the amount after 4 yrs = amount after 3 yrs plus interest for 1 year;

one year =854-815=39 rate of simple interest;

so 3 yrs x 39 simple interest = 117;

so 815-117 = 698

the sum is 698

area = length x width

length = 2 x width

32 = 2 x width x width

32 = 2 x width^2

36 = width ^2  

width = 6

length = 12

area is 32

perimeter = 2 x 12 + 2 x 6 = 24 + 12 = 36

step-by-step explanation:

2: 10

step-by-step explanation: