Answer : Distance between the starting rung and the top most rung =250cm
⇒ Number of rungs in 250 cm with spacing of 25 cm = ( 250 /25) =10
⇒ Including the bottom most rung the total number of rungs on the ladder =11
⇒ The lenght of rungs is an Arithmetic Progression
⇒ Sum of lengths of all 11 rungs =[ ( 1st term + last term) /2 ] × number of rungs = [( 45 + 25 )/2]× 11 =385 cm