If 7a+4 x 5b = 1715 ab =
(a) 0 (b) 2 (c) -1 (d)4

• ans : 0
  
  because 1715 * ab ( anything which is multiple of 5 is either 0 or 5)
  if we go through option we have only o
  so , ans = 0
• 12 years agoHelpfull: Yes(15) No(13)
• ans=-1
  7^(a+4)* 5^b = 1715 = 343*5 = 7^3 * 5^1
  => a+4=3 & b=1
  => a=-1 & b=1
  => ab = -1
• 7 years agoHelpfull: Yes(3) No(1)