Study the following graph carefully to answer the given questions

Q:

M can do a piece of work 5 days less than that of P. M and P began to work together but M leaves after some days and P completed the remaining work in 12 days. Number of days after which M left the job-

• 1
  $$ 5{7\over9}$$
• 2
  $$ 6{7\over9}$$
• 3
  $$ 7{7\over9}$$
• 4
  $$ 11{7\over9}$$
• 5
  None of these