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National and Regional Contests
India Contests
India LIMIT
2020 LIMIT
2020 LIMIT Category 1
3
Sum of Digit sum and digit product
Sum of Digit sum and digit product
Source: LIMIT 2020 Cat 1 Obj P3
May 2, 2020
algebra
limit
Problem Statement
How many
2
2
2
digit number
n
=
a
b
n=ab
n
=
ab
(
a
a
a
and
b
b
b
are digits) have the property that
n
=
a
+
b
+
a
×
b
n=a+b+a\times b
n
=
a
+
b
+
a
×
b
(A)
20
20
20
(B)
15
15
15
(C)
9
9
9
(D)
8
8
8
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