Question

Find the least length of a wire which can be cut into whole number of pieces of lengths 20 cm,45cm and 64 cm​

Answer 1

Answer:

Step-by-step explanation:

To cut an exact number of pieces of 20 cm, 45 cm and 64 cm length from a wire, the wire has to be the length of the LCM of 20, 45 and 64.

20=2*2*5=2²*5

45=3*3*5=3²*5

64=2*2*2*2*2*2=2⁶

LCM=Product of highest power of each prime

=2⁶*3²*5=64*9*5=2880

So, the length of the wire is 2880 cm.

<Hope this helps>

P.s.  If you are in primary school, this is the method you have to use at around 8th standard. I hope you know how to calculate LCM.