A snail, climbing a 42 feet high wall, climbs up 4 feet on the first day but slides down 2 feet on the second. It climbs 4 feet on the third day and slides down again 2 feet on the fourth day. If this pattern continues, how many days will it take the snail to reach the top of the wall?	Choices.
A) 20	B) 26	C) 32	D) 39	E) 51
total transaction in two days = 4-2= 
<gadget id="calculator">4-2</gadget>
<output>2</output>
2 feet   in 38 days it will climb 38 feet   on the 39th day , the snail will climb 4 feet , thus reaching the top   therefore , total no of days required=39   39
<result>D</result>
A snail, climbing a 42 feet high wall, climbs up 4 feet on the first day but slides down 2 feet on the second. It climbs 4 feet on the third day and slides down again 2 feet on the fourth day. If this pattern continues, how many days will it take the snail to reach the top of the wall?