A volcanic lava laterally moves at the rate of 15/4 feet per hour. How

Question

A volcanic lava laterally moves at the rate of 15/4 feet per hour. How many days does it take the lava to move 3/2 mile? (1 mile = 5,280 feet)

(A) 48
(B) 60
(C) 72
(D) 80
(E) 88

MBAHOUSE · Answer

Rule of three made this question easier and the calculations are not that hard.

ThatDudeKnows · Answer

15/4 feet per hour is 15 feet every four hours. That's 90 feet per day. 
We need to go 1.5*5280 = 7920
90days*90feet/day would be 8100. 88*90 is 7920

Answer choice E.

GmatPoint · Answer

Since 1 mile = 5,280 feet, 3/2 mile = 7920 feet.

If volcanic lava is moving at the rate of 15/4 feet per hour,
Time taken to move 7920 feet = 7920/(15/4) = 4*7920/15 =4*528 hours.

Also, as 1 day = 24 hours,
4*528 hours = 4*528/24 days = 88 days.

Thus, the correct option is E.

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