1*6*1 +7*2= (0)shriti wrote:Can someone please explain how to solve this question?..Its from the Manhattan GMAT Quant Question bank
What is the units digit of (71)^5(46)^3(103)^4 + (57) (1088)^3 ?
a. 0
b. 1
c. 2
d. 3
e. 4
Thanks
Unit of Measure
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Unit's digit of (71)^5 = Unit's digit of (1)^5 = 1shriti wrote:What is the units digit of (71)^5(46)^3(103)^4 + (57) (1088)^3 ?
a. 0
b. 1
c. 2
d. 3
e. 4
Unit's digit of (46)^3 = Unit's digit of (6)^3 = 6
Unit's digit of (103)^4 = Unit's digit of (3)^4 = 1
Unit's digit of (1088)^3 = Unit's digit of (8)^3 = 2
Hence, unit's digit of [(71)^5]*[(46)^3]*[(103)^4] + (57)*[(1088)^3]
= unit's digit of (1*6*1 + 57*2)
= unit's digit of (1*6*1 + 7*2)
= unit's digit of (6 + 4)
= unit's digit of 10
= 0
The correct answer is A.
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