A 136 cm cable is cut into 8 circles. The diameter in each circle is difference from one another by 1 cm. Determine: a. The diameter for the biggest circle.

For "a," let the circumference of the smallest circle be "d"

So we have

pi [ (d) + (d+1) + (d+2) + (d+3) + (d+4) + (d+5) + (d+6)  + (d+7 ] = 136     simplify

pi [8d + 28] = 136    divide by pi on both sides

[8d + 28] = 136/pi

8d + 28 =136/pi      subtract 28 from both sides

8d  = 136/pi - 28      divide both sides by 8

d = (136/pi - 28)/ 8  = about 1.91cm     and that's the diameter of the smallest  circle

So....the diameter of the largest circle = 1.91 + 7  = about 8.91 cm

I'm not sure I understand what you're asking in "b".......does anyone else see this ???

The meaning for part b is very unclear.

It might just mean that if the diamerter if the smallest one is 1.19cm and the same pattern continues as before the how many circles can be cut from the new length of cable (2.8m).