`a, M = 1/1 - 1/6 + 1/6 - 1/11 + ... + 1/96 - 1/101`
`= 100/101`
`b, 5N = 5/(1.6) + 5/(6.11) + ... + 5/(51.56)`
`= 1/1 - 1/6 + 1/6 - 1/11 + ... + 1/51 - 1/56`
`= 55/56`
`=> N = 11/56`
\(a,M=\dfrac{5}{1.6}+\dfrac{5}{6.11}+\dfrac{5}{11.16}+....+\dfrac{5}{96.101}\)
\(M=1-\dfrac{1}{6}+\dfrac{1}{6}-\dfrac{1}{11}+\dfrac{1}{11}-\dfrac{1}{16}+...+\dfrac{1}{96}-\dfrac{1}{101}\)
\(M=1-\dfrac{1}{101}\)
\(M=\dfrac{101-1}{101}=\dfrac{100}{101}\)
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\(b,N=\dfrac{1}{1.6}+\dfrac{1}{6.11}+\dfrac{1}{11.16}+...+\dfrac{1}{51.56}\)
\(N=1-\dfrac{1}{6}+\dfrac{1}{6}-\dfrac{1}{11}+\dfrac{1}{11}-\dfrac{1}{16}+...+\dfrac{1}{51}-\dfrac{1}{56}\)
\(N=1-\dfrac{1}{56}\)
\(N=\dfrac{56-1}{56}=\dfrac{55}{56}\)