Question

How many numbers lie between 300 and 2
500 in which 4 comes only one time?
(1) 99
(2) 100
(3) 110
(4) 120​

Answer 1

The number lies between 300 and 500 in which 4 comes only one time are:

300 – 399 = 18

400 – 410 = 10

411 – 420 = 9

421 – 430 = 9

431 – 439 = 8

450 – 460 = 10

461 – 470 = 9

471 – 480 = 9

481 – 490 = 9

491 – 500 = 8

∴ Required number are:

18 + 10 + 9 + 9 + 8 + 10 + 9 + 9 + 9 + 8 = 99