If a and b are odd numbers, then which of the following is even?
a + b + ab
a + b - 1
a + b + 1
a + b + 2ab
What is the least number which when divided by 5, 6, 7, 8 gives the remainder 3 but is divisible by 9?
1463
1573
1683
1793
C.
1683
L.C.M. of 5,6,7,8 = 840.
Required number is of the form 840k + 3.
Least value of k for which (840k + 3) is divisible by 9 is k = 2.
Required number = (840 X 2 + 3)=1683.
The HCF and LCM of two numbers are 12 and 924 respectively. Then the number of such pairs is
0
1
2
3