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Mathematical Skills | Number System

Q. No. 13:pqr is a three digit natural number so that pqr = p!+q!+r!. What is the value of (q+r)p?
A :
1296
B :
3125
C :
19683
D :
9
Q. No. 14:A boy writes all the numbers from 100 to 999. The number of zeroes that he uses is 'a', the number of 5's that he uses is 'b' and the number of 8's he uses is 'c'. What is the value of  b+c-a?
A :
280
B :
380
C :
180
D :
80
Q. No. 15:A chain smoker had spent all the money he had. He had no money to buy his cigarettes. Hence, he resorted to join the stubs and to smoke them. He needed 4 stubs to make a single cigarettes. If he got a pack of 10 cigarettes as a gift, then how many cigarettes could he smoke in all?
A :
10
B :
11
C :
12
D :
13
Q. No. 16:A bank issued credit card numbers and the corresponding PIN (Personal Identification Number). Both are 3-digit numbers up to 996. Pinaki was the last to get the credit card and so he had  the last possible credit card number. He was afraid of forgetting his PIN. He wrote down the number 123 in his diary to remember his PIN. He also wrote out the way to calculate 123 : "Multiply the card number by PIN. Divide the product by 997. The remainder is 123". Once, Prafull saw his diary in which Pinaki wrote this number 123. Prafull did a lot of purchasing, as he now knows Pinaki's PIN. What is Pinaki's PIN?
A :
874
B :
875
C :
876
D :
877
 16  123
Number System
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