Question

A stack of boards is in the storage shed. Each board is 2-1/5 inches high and there are 21 boards. How many inches high is the stack?

a
231/2
b
46-1/5
c
42-1/5
d
231/5

Answer 1

b) 46⅕

d) 231/5

Explanation:

2⅕ = 11/5

(11/5) × 21

= 231/5

= 46⅕

Answer 2

46 1/5 inches tall

Explanation:

We know each board is 2 1/5 inches high

Change this to an improper fraction

2 1/5 = (5*2+1)/5 = 11/5

Multiply this by the number of boards

11/5 * 21 = 231/5

Change this back to a mixed number

5 goes into 231 46 times

46*5 = 230 there is 1 left over

46 1/5 inches tall