A rectangular garden with length 85 metre and breadth 60 metre has to two cross road . One Cross Road is 4 metre wide and it parallel to the length and other cross Road is 3.5 metre wide and it parallel to the breadth of the garden .Find the cost of constructing these crossroad at rupees 17 per square metre​

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

it is a. 4.2 because 7.6-3.4 gets the remaining length of 4.2. i might be wrong but i am pretty sure this is the answer.

explanation:

infrared radiation has wavelength in the range between 700 nm and 1 mm. lets' convert these values into scientific notation, keeping in mind that:

let's start from the lower value, we have:

(we moved the dot two places to the left, so we increased the exponent by 2 units, from -9 to -7)

the higher value is:

so, the range of wavelength of infrared radiation is: