Question

2+5=336;3+6=720;4+7=1120;5+8=?​

Answer 1

Given:

2 + 5 = 336, 3 + 6 = 720, 4 + 7 = 1320

We have to find, the value of 5 + 8 = ?​

Solution:

The pattern follow:

$(Sum of numbers)^{3}$ - (Sum of numbers).

336 = $(2+5)^{3}$ - (2 + 5) = $7^{3}$ - 7

= 343 - 7 = 336

720 = $(3+6)^{3}$ - (3 + 6) = $9^{3}$ - 9

= 729 - 9 = 720

1320 = $(4+7)^{3}$ - (5 + 8) = $11^{3}$ - 11

= 1331 - 11 = 1320

Similarly,

?​ =  $(5+8)^{3}$ - (5 + 8) = $13^{3}$ - 13

= 2197 - 13 = 2184

∴ Missing number (?) = 2184

Thus, if 2 + 5 = 336, 3 + 6 = 720, 4 + 7 = 1320, then "5 + 8 = 2184".